Online Etymology Dictionary

gregarious (adj.): 1660s, "disposed to live in flocks" (of animals), from Latin gregarius "pertaining to a flock; of the herd, of the common sort, common," from grex (genitive gregis) "flock, herd," from PIE *gre-g-, reduplicated form of root *ger- (1) "to gather together, assemble" (source also of Sanskrit gramah "heap, troop;" Greek ageirein "to assemble," agora "assembly;" Latin gremium "bosom, lap;" Old Church Slavonic grusti "handful," gramota "heap;" Lithuanian gurgulys "chaos, confusion," gurguole "crowd, mass"). Of persons, "sociable" first recorded 1789. Related: Gregariously; gregariousness.
timocracy (n.): 1580s, from Middle French tymocracie, from Medieval Latin timocratia (13c.), from Greek timokratia, from time "honor, worth" (related to tiein "to place a value on, to honor," from PIE *kwi-ma-, suffixed form of root *kweie- (1) "to value, honor") + -kratia "rule" (see -cracy). In Plato's philosophy, a form of government in which ambition for honor and glory motivates the rulers (as in Sparta). In Aristotle, a form of government in which political power is in direct proportion to property ownership. Related: Timocratic; timocratical.
perdition (n.): mid-14c., "fact of being lost or destroyed," from Old French perdicion "loss, calamity, perdition" of souls (11c.) and directly from Late Latin perditionem (nominative perditio) "ruin, destruction," noun of action from past participle stem of Latin perdere "do away with, destroy; lose, throw away, squander," from per- "through" (here perhaps with intensive or completive force, "to destruction") + dare "to put" (see date (n.1)). Special theological sense of "condition of damnation, spiritual ruin, state of souls in Hell" (late 14c.) has gradually extinguished the general use of the word.
perspective (n.): late 14c., "science of optics," from Old French perspective and directly from Medieval Latin perspectiva ars "science of optics," from fem. of perspectivus "of sight, optical" from Latin perspectus "clearly perceived," past participle of perspicere "inspect, look through, look closely at," from per- "through" (see per) + specere "look at" (see scope (n.1)). Sense of "art of drawing objects so as to give appearance of distance or depth" is first found 1590s, influenced by Italian prospettiva, an artists' term. The figurative meaning "mental outlook over time" is first recorded 1762.
pessimism (n.): 1794 "worst condition possible," borrowed (by Coleridge) from French pessimisme, formed (on model of French optimisme) from Latin pessimus "worst," originally "bottom-most," from PIE *ped-samo-, superlative of root *pes- "foot," from PIE root *ped- (1) "a foot" (see foot (n.)). As a name given to the doctrines of Schopenhauer, Hartmann, etc., that this is the worst possible world, or that everything tends toward evil, it is first recorded 1835, from German pessimismus (Schopenhauer, 1819). The attempt to make a verb of it as pessimize (1862) did not succeed.
hospice (n.): 1818, "rest house for travelers," especially the houses of refuge and shelter kept by monks in the passes of the Alps, from French hospice "hospital, almshouse" (Old French ospice "hospice, shelter," also "hospitality," 13c.), from Latin hospitium "hospitable reception, entertainment; hospitality, bonds of hospitality, relationship of guest and host;" also "place of entertainment, lodging, inn, guest-house," from hospes (genitive hospitis) "guest; host," also "a stranger, foreigner" (see host (n.1)).

Sense of "home for the aged and terminally ill " is from 1879; hospice movement first attested 1978.
hostage (n.): late 13c., from Old French ostage, hostage "kindness, hospitality; residence, dwelling; rent, tribute; compensation; guarantee, pledge, bail; person given as security or hostage" (11c., Modern French ôtage), which is of uncertain origin. Either from hoste "guest" (see host (n.1)) via notion of "a lodger held by a landlord as security" [Watkins, Barnhart]; or else from Late Latin obsidanus "condition of being held as security," from obses "hostage," from ob- "before" + base of sedere "to sit," with spelling influenced by Latin hostis. [OED, Century Dictionary]. Modern political/terrorism sense is from 1970.
exchequer (n.): c. 1300, from Anglo-French escheker "a chessboard," from Old French eschequier, from Medieval Latin scaccarium "chess board" (see check (n.1); also see checker (n.2)). Government financial sense began under the Norman kings of England and refers to a cloth divided in squares that covered a table on which accounts of revenue were reckoned with counters, and which apparently reminded people of a chess board. Respelled with an -x- based on the mistaken belief that it originally was a Latin ex- word.
respect (n.): late 14c., "relationship, relation; regard, consideration," from Old French respect and directly from Latin respectus "regard, a looking at," literally "act of looking back (or often) at one," noun use of past participle of respicere "look back at, regard, consider," from re- "back" (see re-) + specere "look at" (see scope (n.1)). Meanings "feeling of esteem excited by actions or attributes of someone or something; courteous or considerate treatment due to personal worth or power" are from 1580s, as is sense of "point, particular feature."
express (v.1): late 14c., "represent in visual arts; put into words," from Old French espresser, expresser "press, squeeze out; speak one's mind" (Modern French exprimer), Medieval Latin expressare, frequentative of Latin exprimere "represent, describe, portray, imitate, translate," literally "to press out" (source also of Italian espresso); the sense evolution here perhaps is via an intermediary sense such as "clay, etc., that under pressure takes the form of an image," from ex- "out" (see ex-) + pressare "to press, push," from Latin premere (see press (v.1)). Related: Expressed; expresses; expressing; expressible.
phantasm (n.): early 13c., fantesme, from Old French fantosme "a dream, illusion, fantasy; apparition, ghost, phantom" (12c.), and directly from Latin phantasma "an apparition, specter," from Greek phantasma "image, phantom, apparition; mere image, unreality," from phantazein "to make visible, display," from stem of phainein "to bring to light, make appear; come to light, be seen, appear; explain, expound, inform against; appear to be so," from PIE root *bha- (1) "to shine" (source also of Sanskrit bhati "shines, glitters," Old Irish ban "white, light, ray of light"). Spelling conformed to Latin from 16c. (see ph). A spelling variant of phantom, "differentiated, but so that the differences are elusive" [Fowler].
phlegm (n.): late 14c., fleem "viscid mucus" (the stuff itself and also regarded as a bodily humor), from Old French fleume (13c., Modern French flegme), from Late Latin phlegma, one of the four humors of the body, from Greek phlegma "humor caused by heat," lit "inflammation, heat," from phlegein "to burn," related to phlox (genitive phlogos) "flame, blaze," from PIE *bhleg- "to shine, flash," from root *bhel- (1) "to shine, flash, burn" (see bleach (v.)). Modern form is attested from c. 1660. The "cold, moist" humor of the body, in medieval physiology, it was believed to cause apathy.
robust (adj.): 1540s, from Middle French robuste (14c.) and directly from Latin robustus "strong and hardy," literally "as strong as oak," originally "oaken," from robur, robus "hard timber, strength," also "a special kind of oak," named for its reddish heartwood, from Latin ruber "red" (related to robigo "rust"), from PIE *reudh- (see red (adj.1)). Related: Robustly; robustness. Robustious (1540s) was a common form in 17c. (see "Hamlet" iii.2); it fell from use by mid-18c., but was somewhat revived by mid-19c. antiquarian writers.
rock (v.2): "to dance to popular music with a strong beat," 1948 (first attested in song title "We're gonna rock"), from rock (v.1), in earlier blues slang sense of "to cause to move with musical rhythm" (1922); often used at first with sexual overtones (as in 1922 song title "My Man Rocks Me (with One Steady Roll)"). Sense developed early 1950s to "play or dance to rock and roll music." Related: Rocked; rocking. Rocksteady, Jamaican pop music style (precursor of reggae), is attested from 1969.
apply (v.): late 14c., "to put (one's faculties, etc.) to some task or career," late 14c., from Old French aploiier "apply, use, attach" (12c., Modern French appliquer), from Latin applicare "attach to, join, connect;" figuratively, "devote (oneself) to, give attention," from ad- "to" (see ad-) + plicare "fold" (see ply (v.1)). The etymological sense is "bring things in contact with one another." Of lotions, from early 15c. Meaning "seek a job by submitting an application for one" is from 1851. A by-form applicate is recorded from 1530s. Related: Applied; applying.
monoceros (n.): c. 1300, "the unicorn," from Old French monoceros "unicorn," from Latin monoceros, from Greek monokeros, from mono- "single" (see mono-) + keras "horn of an animal," from PIE *ker- (1) "horn, head" (see horn (n.)).
This is a modern constellation, generally supposed to have been first charted by Bartschius as Unicornu; but Olbers and Ideler say that it was of much earlier formation, the latter quoting allusions to it, in the work of 1564, as "the other Horse south of the Twins and the Crab"; and Scaliger found it on a Persian sphere. [Richard Hinckley Allen, "Star Names and Their Meanings," London: 1899]
portmanteau (n.): 1580s, "traveling case or bag for clothes and other necessaries," from Middle French portemanteau "traveling bag," originally "court official who carried a prince's mantle" (1540s), from porte, imperative of porter "to carry" (see porter (n.1)) + manteau "cloak" (see mantle (n.)).

Portmanteau word "word blending the sound of two different words" (1882), coined by "Lewis Carroll" (Charles L. Dodgson, 1832-1898) for the sort of words he invented for "Jabberwocky," on notion of "two meanings packed up into one word." As a noun in this sense from 1872.
plight (n.1): "condition or state (usually bad)," late 12c., "danger, harm, strife," from Anglo-French plit, pleit, Old French pleit, ploit "condition" (13c.), originally "way of folding," from Vulgar Latin *plictum, from Latin plicitum, neuter past participle of Latin plicare "to fold, lay" (see ply (v.1)).

Originally in neutral sense (as in modern French en bon plit "in good condition"), sense of "harmful state" (and current spelling) probably is from convergence and confusion with plight (n.2) via notion of "entangling risk, pledge or promise with great risk to the pledger."
rosary (n.): "rose garden," mid-15c., from Latin rosarium "rose garden," in Medieval Latin also "garland; string of beads; series of prayers," from noun use of neuter of rosarius "of roses," from rosa "rose" (see rose (n.1)).

The sense of "series of prayers" is 1540s, from Middle French rosaire, a figurative use of the word meaning "rose garden," on the notion of a "garden" of prayers. This probably embodies the medieval conceit of comparing collections to bouquets (compare anthology and Medieval Latin hortulus animae "prayerbook," literally "little garden of the soul"). Sense transferred 1590s to the strings of beads used as a memory aid in reciting the rosary.
article (n.): c. 1200, "separate parts of anything written" (such as the statements in the Apostles' Creed, the clauses of a statute or contract), from Old French article (13c.), from Latin articulus, diminutive of artus "a joint" (from PIE *ar-tu-, from *ar- "to fit together;" (see arm (n.1)).

Meaning extended to "a small division," then generalized to "item, thing." Older sense preserved in Articles of War "military regulations" (1716) and Articles of Confederation (U.S. history). Meaning "literary composition in a journal, etc." (independent, but part of a larger work) first recorded 1712. Meaning "piece of property" (clothing, etc.) first attested 1796, originally in rogue's cant.
rural (adj.): early 15c., from Old French rural (14c.), from Latin ruralis "of the countryside," from rus (genitive ruris) "open land, country," from PIE *reue- (1) "to open; space" (see room (n.)).
In early examples, there is usually little or no difference between the meanings of rural and rustic, but in later use the tendency is to employ rural when the idea of locality (country scenes, etc.) is prominent, and rustic when there is a suggestion of the more primitive qualities or manners naturally attaching to country life. [OED]
Related: Rurally.
tractor (n.): 1856, "something that pulls," from Modern Latin tractor "that which draws," agent noun from past participle stem of Latin trahere "to pull, draw" (see tract (n.1)). Earlier used of a quack device consisting of two metal rods which were supposed to relieve rheumatism (1798, in full Perkins's metallic tractor); still the main sense in Century Dictionary (1891).

Sense of "an engine or vehicle for pulling wagons or plows" is recorded by 1896, from earlier traction engine (1859). The meaning "powerful truck for pulling a freight trailer" is first found 1926; tractor-trailer as "combined motor-truck and trailer" is from 1914.
aristocracy (n.): 1560s, from Middle French aristocracie (Modern French aristocratie), from Late Latin aristocratia, from Greek aristokratia "government or rule of the best," from aristos "best" (originally "most fitting," from PIE *ar-isto-, superlative form of *ar- "to fit together;" see arm (n.1)) + kratos "rule, power" (see -cracy).

At first in a literal sense of "government by those who are the best citizens;" meaning "rule by a privileged class" (best-born or best-favored by fortune) is from 1570s and became paramount 17c. Hence, the meaning "patrician order" (1650s). In early use contrasted with monarchy; after French and American revolutions, with democracy.
model (n.): 1570s, "likeness made to scale; architect's set of designs," from Middle French modelle (16c., Modern French modèle), from Italian modello "a model, mold," from Vulgar Latin *modellus, from Latin modulus "a small measure, standard," diminutive of modus "manner, measure" (see mode (n.1)).

Sense of "thing or person to be imitated" is 1630s. Meaning "motor vehicle of a particular design" is from 1900 (such as Model T, 1908; Ford's other early models included C, F, and B). Sense of "artist's model" is first recorded 1690s; that of "fashion model" is from 1904. German, Swedish modell, Dutch, Danish model are from French or Italian.
modern (adj.): c. 1500, "now existing;" 1580s, "of or pertaining to present or recent times;" from Middle French moderne (15c.) and directly from Late Latin modernus "modern" (Priscian, Cassiodorus), from Latin modo "just now, in a (certain) manner," from modo (adv.) "to the measure," ablative of modus "manner, measure" (see mode (n.1)). Extended form modern-day attested from 1909.

In Shakespeare, often with a sense of "every-day, ordinary, commonplace." Slang abbreviation mod first attested 1960. Modern art is from 1807 (by contrast to ancient); modern dance first attested 1912; first record of modern jazz is from 1954. Modern conveniences first recorded 1926.
modesty (n.): 1530s, "freedom from exaggeration, self-control," from Middle French modestie or directly from Latin modestia "moderation, sense of honor, correctness of conduct," from modestus "moderate, keeping measure, sober, gentle, temperate," from modus "measure, manner" (see mode (n.1)). Meaning "quality of having a moderate opinion of oneself" is from 1550s; that of "womanly propriety" is from 1560s.
La pudeur donne des plaisirs bien flatteurs à l'amant: elle lui fait sentir quelles lois l'on transgresse pour lui; (Modesty both pleases and flatters a lover, for it lays stress on the laws which are being transgressed for his sake.) [Stendhal "de l'Amour," 1822]
moist (adj.): late 14c., "moist, wet; well-irrigated," from Old French moiste "damp, wet, soaked" (13c., Modern French moite), from Vulgar Latin *muscidus "moldy," also "wet," from Latin mucidus "slimy, moldy, musty," from mucus "slime" (see mucus). Alternative etymology [Diez] is from Latin musteus "fresh, green, new," literally "like new wine," from musteum "new wine" (see must (n.1)). If this wasn't the source, it influenced the form of the other word in Old French. Related: Moistly; moistness.
stack (n.): c. 1300, "pile, heap, or group of things," from a Scandinavian source akin to Old Norse stakkr "haystack" (cognate with Danish stak, Swedish stack "heap, stack"), from Proto-Germanic *stakon- "a stake," from PIE *stog- (source also of Old Church Slavonic stogu "heap," Russian stog "haystack," Lithuanian stokas "pillar"), variant of root *steg- (1) "pole, stick" (see stake (n.)). Meaning "set of shelves on which books are set out" is from 1879. Used of the chimneys of factories, locomotives, etc., since 1825. Of computer data from 1960.
stagger (v.): mid-15c., "walk unsteadily, reel" (intransitive), altered from stakeren (early 14c.), from a Scandinavian source (compare Old Danish stagra, Old Norse stakra "to push, shove, cause to reel," also "to stumble, stagger," perhaps literally "hit with a stick," from Proto-Germanic *stakon- "a stake," from PIE *steg- (1) "pole, stick." Cognate with Dutch staggelen "to stagger," German staggeln "to stammer." Transitive sense of "bewilder, amaze" first recorded 1550s; that of "arrange in a zig-zag pattern" is from 1856. Related: Staggered; staggering.
pressure (n.): late 14c., "suffering, anguish; act or fact of pressing on the mind or heart," from Old French presseure "oppression; torture; anguish; press" (for wine or cheeses), "instrument of torture" (12c.) and directly from Latin pressura "action of pressing," from pressus, past participle of premere "to press" (see press (v.1)).

Literal meaning "act or fact of pressing" in a physical sense is attested from early 15c. Meaning "moral or mental coercing force" is from 1620s; meaning "urgency" is from 1812. Scientific sense in physics is from 1650s. Pressure cooker is attested from 1915; figurative sense is from 1958. Pressure point is attested from 1876. Pressure-treated, of woods, is from 1911.
court (n.): late 12c., from Old French cort (11c., Modern French cour) "king's court, princely residence," from Latin cortem, accusative of cors (earlier cohors) "enclosed yard," and by extension (and perhaps by association with curia "sovereign's assembly"), "those assembled in the yard; company, cohort," from com- "together" (see com-) + stem hort- related to hortus "garden, plot of ground" (see yard (n.1)). Sporting sense is from 1510s, originally of tennis. Legal meaning is from late 13c. (early assemblies for justice were overseen by the sovereign personally).
sockdolager (n.): 1830, "a decisive blow" (also, figuratively "a conclusive argument"), fanciful formation from sock (v.1) "hit hard," perhaps via a comical mangling of doxology, on a notion of "finality." The meaning "something exceptional" is attested from 1838.

Sockdologising likely was nearly the last word President Abraham Lincoln heard. During the performance of Tom Taylor's "Our American Cousin," assassin John Wilkes Booth (who knew the play well) waited for the laugh-line "Well, I guess I know enough to turn you inside out, you sockdologising old man-trap." Amid the noise as the audience responded, Booth fired the fatal shot.
soil (n.1): c. 1300, originally "land, area, place," from Anglo-French soil "piece of ground, place" (13c.), from an merger or confusion of Old French sol "bottom, ground, soil" (12c., from Latin solum "soil, ground;" see sole (n.1)), Old French soeul, sueil "threshold, area, place" (from Latin solium "seat"), and Old French soil, soille "a miry place," from soillier (see soil (v.)).

Meaning "place of one's nativity" is from c. 1400. Meaning "mould, earth, dirt" (especially that which plants grow in) is attested from mid-15c.
spade (n.2): black figure on playing cards," 1590s, probably from Italian spade, plural of spada "the ace of spades," literally "sword, spade," from Latin spatha "broad, flat weapon or tool," from Greek spathe "broad blade" (see spade (n.1)). Phrase in spades "in abundance" first recorded 1929 (Damon Runyon), probably from bridge, where spades are the highest-ranking suit.
The invitations to the musicale came sliding in by pairs and threes and spade flushes. [O.Henry, "Cabbages & Kings," 1904]
Derogatory meaning "black person" is 1928, from the color of the playing card symbol.
species (n.): late 14c. as a classification in logic, from Latin species "a particular sort, kind, or type" (opposed to genus), originally "a sight, look, view, appearance," hence also "a spectacle; mental appearance, idea, notion; a look; a pretext; a resemblance; a show or display," typically in passive senses; in Late Latin, "a special case;" related to specere "to look at, to see, behold," from PIE *spek- (see scope (n.1)). From 1550s as "appearance, outward form;" 1560s as "distinct class (of something) based on common characteristics." Biological sense is from c. 1600. Endangered species first attested 1964.
speculation (n.): late 14c., "intelligent contemplation, consideration; act of looking," from Old French speculacion "close observation, rapt attention," and directly from Late Latin speculationem (nominative speculatio) "contemplation, observation," noun of action from Latin speculatus, past participle of speculari "observe," from specere "to look at, view" (see scope (n.1)).

Meaning "pursuit of the truth by means of thinking" is from mid-15c. Disparaging sense of "mere conjecture" is recorded from 1570s. Meaning "buying and selling in search of profit from rise and fall of market value" is recorded from 1774; short form spec is attested from 1794.
tail-gate (n.): 1868, back panel on a wagon, hinged to swing down and open, from tail (n.1) + gate (n.). Extended by 1950 to hatchback door on an automobile. The verb (also tailgate) meaning "to drive too close behind another vehicle" is from 1951 ("Truck drivers know the practice of following too close as tail-gating" - "Popular Science," Jan. 1952); as an adjective, in reference to the open tail-gate of a parked car as a setting for a party or picnic, from 1958. Related: Tail-gating.
spike (v.): 1620s, "to fasten with spikes," from spike (n.1). Meaning "to rise in a spike" is from 1958. Military sense (1680s) means "to disable guns by driving a large nail into the touch-hole." Figurative use of this sense is from 1823. Meaning "to lace (a drink) with liquor" is from 1889. Journalism sense of "to kill a story before publication" (1908) is from the metal spindle in which old-time editors filed hard copy of stories after they were set in type, or especially when rejected for publication. Related: Spiked; spiking.
stilt (n.): early 14c., "a crutch," a common Germanic word (cognates: Danish stylte, Swedish stylta, Middle Low German, Middle Dutch stelte "stilt," Old High German stelza "plow handle, crutch"), though the exact relationship of them all is unclear, from Proto-Germanic *steltijon, from PIE root *stel- "to put, stand" (see stall (n.1)). Application to "wooden poles for walking across marshy ground, etc." is from mid-15c. Meaning "one of the posts on which a building is raised from the ground" is first attested 1690s. As a type of bird with long legs, from 1831. Stilted in the figurative sense of "pompous, stuffy" is first recorded 1820.
scallop (n.): "bivalve mollusk," c. 1400, from Old French escalope "shell (of a nut), carpace," variant of eschalope, probably from a Germanic source (compare Old Norse skalpr "sheath," Middle Dutch schelpe "shell"); see scale (n.1). The shells of the larger species have been used as domestic utensils. Extended 17c. to objects shaped like scallop shells, especially in design and dress. The verb in the cookery sense, "to bake with sauce in a scallop shell-shaped pan," is attested from 1737. Related: Scalloped; scalloping.
stapes (n.): "stirrup-shaped bone in the middle ear," 1660s, from Modern Latin (1560s), special use of Medieval Latin stapes "stirrup," probably an alteration of Late Latin stapia, related to stare "to stand," from PIE root *stā- "to stand, set down, make or be firm" (see stet) + pedem, accusative of pes "foot," from PIE root *ped- (1) "a foot" (see foot (n.)). This was an invented Medieval Latin word for "stirrup," for which there was no classical Latin word, as the ancients did not use stirrups.
strip (n.): "long, narrow, flat piece," mid-15c., "narrow piece of cloth," probably related to or from Middle Low German strippe "strap, thong," and from the same source as stripe (n.1). Sense extension to wood, land, etc. first recorded 1630s.

Sense in comic strip is from 1920. Airport sense is from 1936; race track sense from 1941. Meaning "street noted for clubs, bars, etc." is attested from 1939, originally in reference to Los Angeles' Sunset Strip. Strip mine (n.) attested by 1892, as a verb by 1916; so called because the surface material is removed in successive parallel strips.
supper (n.): mid-13c., soper, "the last meal of the day," from Old French soper "evening meal," noun use of infinitive soper "to eat the evening meal," which is of Germanic origin (see sup (v.1)).
Formerly, the last of the three meals of the day (breakfast, dinner, and supper); now applied to the last substantial meal of the day when dinner is taken in the middle of the day, or to a late meal following an early evening dinner. Supper is usually a less formal meal than late dinner. [OED]
Applied since c. 1300 to the last meal of Christ.
suspect (adj.): early 14c., "suspected of wrongdoing, under suspicion;" mid-14c., "regarded with mistrust, liable to arouse suspicion," from Old French suspect (14c.), from Latin suspectus "suspected, regarded with suspicion or mistrust," past participle of suspicere "look up at, look upward," figuratively "look up to, admire, respect;" also "look at secretly, look askance at," hence, figuratively, "mistrust, regard with suspicion," from assimilated form of sub "up to" (see sub-) + specere "to look at" (see scope (n.1)). The notion behind the word is "look at secretly," hence, "look at distrustfully."
samizdat (n.): "illegal and clandestine copying and sharing of literature," 1967, from Russian samizdat, literally "self-publishing," from sam "self" (see same) + izdatel'stvo "publishing" (from iz "from, out of," from PIE *eghs; see ex-; + dat' "to give," from PIE *do-; see date (n.1)). Said to be a word-play on Gosizdat, the former state publishing house of the U.S.S.R. One who took part in it was a samizdatchik (plural samizdatchiki). Later and less common was tamizdat "writings published abroad and smuggled back into the U.S.S.R.," from tam "there."
serial (adj.): "coming in regular succession," 1840, from series + -al (1); popularized in reference to Dickens' novels, published one part at a time in periodicals (as opposed to all at once in a book). Found to be a useful word and given wide application. Serial number, indicating position in a series, first recorded 1866, originally of papers, packages, etc.; of soldiers from 1918. Serial killer is first attested 1981 (in relation to John Wayne Gacy and Ted Bundy), though serial had been used in connection with murders since the early 1960s. Related: Serially.
skat (n.): card game, 1864, from German Skat (by 1838), from earlier scart (said to have been a term used in the old card game called taroc, which was of Italian origin), from Italian scarto "cards laid aside," which is said to be a back-formation from scartare, from Latin ex- "off, away" + Late Latin carta (see card (n.1)). The German game is perhaps so called because it is played with a rump deck, or because two cards are laid aside at the start of the game, or because discarding is an important part of the game. Compare French card game écarté, literally "cards removed."
scum (n.): early 14c. (implied in scummer "shallow ladle for removing scum"), from Middle Dutch schume "foam, froth," from Proto-Germanic *skuma- (source also of Old Norse skum, Old High German scum, German Schaum "foam, froth"), perhaps from PIE root *(s)keu- "to cover, conceal" (see hide (n.1)).

Sense deteriorated from "thin layer atop liquid" to "film of dirt," then just "dirt." Meaning "lowest class of humanity" is 1580s; scum of the Earth is from 1712. Adopted in Romanic (Old French escume, Modern French écume, Spanish escuma, Italian schiuma).
seal (v.): "to fasten with (or as with) a seal," c. 1200, from seal (n.1). Meaning "to place a seal on (a document)" is recorded from mid-14c.; hence "to conclude, ratify, render official" (late 15c.). Sense of "to close up with wax, lead, cement, etc." is attested from 1660s, from the notion of wax seals on envelopes. In reference to the actions of wood-coatings, 1940. Related: Sealed; sealing. Sealing-wax is attested from c. 1300. To seal (one's) fate (1799) probably reflects the notion of a seal on an execution warrant.
sect (n.): mid-14c., "distinctive system of beliefs or observances; party or school within a religion," from Old French secte, sete "sect, religious community," or directly from Late Latin secta "religious group, sect in philosophy or religion," from Latin secta "manner, mode, following, school of thought," literally "a way, road, beaten path," from fem. of sectus, variant past participle of sequi "follow," from PIE *sekw- (1) "to follow" (see sequel). Confused in this sense with Latin secta, fem. past participle of secare "to cut" (see section (n.)). Meaning "separately organized religious body" is recorded from 1570s.