Online Etymology Dictionary

enigma (n.): 1530s, "statement which conceals a hidden meaning or known thing under obscure words or forms," earlier enigmate (mid-15c.), from Latin aenigma "riddle," from Greek ainigma (plural ainigmata) "a dark saying, riddle," from ainissesthai "speak obscurely, speak in riddles," from ainos "tale, story; saying, proverb;" according to Liddell & Scott, a poetic and Ionic word, of unknown origin. General sense in English of "anything inexplicable to an observer" is from c. 1600.
enmity (n.): late 14c., "hostile feeling, rivalry, malice; internal conflict," from Old French enemite, variant of enemistié "enmity, hostile act, aversion" (Modern French inimité), from Vulgar Latin *inimicitatem (nominative *inimicitas), from Latin inimicitia "enmity, hostility," usually plural, from inimicus "enemy" (see enemy). Related: Enmities. Amity is basically the same word without the negative prefix.
akimbo: c. 1400, in kenebowe, of unknown origin, perhaps from Middle English phrase in keen bow "at a sharp angle," or from a Scandinavian word akin to Icelandic kengboginn "bow-bent," but this seems not to have been used in this exact sense. Many languages use a teapot metaphor for this, such as French faire le pot a deux anses "to play the pot with two handles."
alarm (n.): early 14c., from Old French alarme (14c.), from Italian all'arme "to arms!" (literally "to the arms"). An interjection that came to be used as the word for the call or warning (compare alert). Extended 16c. to "any sound to warn of danger or to arouse." Weakened sense of "apprehension, unease" is from 1833. Variant alarum is due to the rolling -r- in the vocalized form. Sometimes in early years Englished as all-arm. Alarm clock is attested from 1690s (as A Larum clock).
Albania: Medieval Latin name of the country called by its inhabitants Shqipëri (literally "land of eagles," from shqiponje "eagle"), from Medieval Greek Albania, possibly from a pre-IE word *alb "hill" (also proposed as the source of Alps) or from the PIE root *albho- "white" (see alb). Roman Albania was a land by the Caspian Sea (modern Daghestan); in English Albania was occasionally also a name for Scotland.
allure (v.): c. 1400, from Anglo-French alurer, Old French aleurer "to attract, captivate; train a falcon to hunt," from à "to" (see ad-) + loirre "falconer's lure," from a Frankish word (see lure), perhaps influenced by French allure "gait, way of walking." Related: Allured; alluring. The noun is first attested 1540s; properly this sense is allurement.
dial (n.): early 15c., "sundial," earlier "dial of a compass" (mid-14c.), apparently from Medieval Latin dialis "daily," from Latin dies "day" (see diurnal).

The word perhaps was abstracted from a phrase such as Medieval Latin rota dialis "daily wheel," and evolved to mean any round plate over which something rotates. Telephone sense is from 1879, which led to dial tone (1921), "the signal to begin dialing," which term soon might be the sole relic of the rotary phone.
dieresis (n.): also diaeresis, 1610s, "sign marking the division of a diphthong into two simple sounds," from Late Latin diaeresis, from Greek diairesis "division," noun of action from diairein "to divide, separate," from dia- "apart" (see dia-) + hairein "to take" (see heresy). In classical prosody, "the slight break in the forward motion of a line that is felt when the end of a foot coincides with the end of a word" [Miller Williams, "Patterns of Poetry"].
dimple (n.): c. 1400, perhaps existing in Old English as a word meaning "pothole," perhaps ultimately from Proto-Germanic *dumpilaz, which has yielded words in other languages meaning "small pit, little pool" (such as German Tümpel "pool," Middle Low German dümpelen, Dutch dompelen "to plunge"). Related: Dimples.
nod (v.): "to quickly bow the head," late 14c., of unknown origin, probably an Old English word, but not recorded; perhaps related to Old High German hnoton "to shake," from Proto-Germanic *hnudan. Meaning "to drift in and out of consciousness while on drugs" is attested from 1968. Related: Nodded; nodding. A nodding acquaintance (1711) is one you know just well enough to greet with a nod.
omnibus (n.): 1829, "four-wheeled public vehicle with seats for passengers," from French (voiture) omnibus "(carriage) for all, common (conveyance)," from Latin omnibus "for all," dative plural of omnis "all" (see omni-). Introduced by Jacques Lafitte in Paris in 1819 or '20, in London from 1829. In reference to legislation, the word is recorded from 1842. Meaning "man or boy who assists a waiter at a restaurant" is attested from 1888 (compare busboy). As an adjective in English from 1842.
inkhorn (n.): late 14c., "small portable vessel (originally made of horn) for holding ink," from ink (n.) + horn (n.). Used attributively from 1540s ("Soche are your Ynkehorne termes," John Bale) as an adjective for things (especially vocabulary) supposed to be beloved by scribblers, pedants, and bookworms. An Old English word for the thing was blæchorn.
inset (n.): 1550s, "influx of water; place where water flows in," from in (prep.) + set (n.2). The later word in a sense "that which is set in" ("extra pages of a book, etc.," 1871; "small map in the border of a larger one," 1872) probably are a separate formation. In Old English insetan (Old Northumbrian insetta) meant "an institution," literally "a setting in," and perhaps a loan-translation of the source of institution. Similar formation in German einsetzen "to use, employ; institute, begin; install."
insurance (n.): 1550s, "engagement to marry," a variant of ensurance "an assurance, pledge, guarantee," from Old French enseurance "assurance," from ensurer, from en- "make" (see en- (1)) + sur "safe, secure, undoubted" (see sure (adj.)).

Commercial sense of "security against loss or death in exchange for payment" is from 1650s. Assurance was the older word for this specific sense (late 16c.). Compare insure.
integer (n.): "a whole number" (as opposed to a fraction), 1570s, from Latin integer (adj.) "intact, whole, complete," figuratively, "untainted, upright," literally "untouched," from in- "not" (see in- (1)) + root of tangere "to touch," from PIE root *tag- "to touch, handle" (see tangent (adj.)). The word was used earlier in English as an adjective in the Latin sense, "whole, entire" (c. 1500).
intellect (n.): "the sum of the cognitive facilities (except sense or sense and imagination), the capacity for reasoning truth," late 14c. (but little used before 16c.), from Old French intellect "intellectual capacity" (13c.), and directly from Latin intellectus "discernment, a perception, understanding," noun use of past participle of intelligere "to understand, discern" (see intelligence). The Latin word was used to translate Greek nous "mind, thought, intellect" in Aristotle.
equivocation (n.): late 14c., "fallacy of using a word in different senses at different stages of the reasoning" (a loan-translation of Greek homonymia, literally "having the same name"), from Old French equivocation, from Late Latin aequivocationem (nominative aequivocatio), noun of action from aequivocus "of identical sound, of equal voice, of equal significance, ambiguous, of like sound," past participle of aequivocare, from aequus "equal" (see equal (adj.)) + vocare "to call" (see voice (n.)).
flaunt (v.): 1560s, "to display oneself in flashy clothes," of unknown origin. Perhaps a variant of flout or vaunt. Perhaps from Scandinavian, where the nearest form seems to be Swedish dialectal flankt "loosely, flutteringly," from flakka "to waver" (related to flag (v.1)). It looks French, but it corresponds to no known French word. Transitive sense, "flourish (something), show off, make an ostentatious or brazen display of" is from 1827. Related: Flaunted; flaunting; Flauntingly.
gook (n.): 1899, U.S. military slang for "Filipino" during the insurrection there, probably from a native word, or imitative of the babbling sound of a strange language to American ears (compare barbarian). The term goo-goo eyes "soft, seductive eyes" was in vogue c. 1900 and may have contributed to this somehow. Extended over time to "Nicaraguan" (U.S. intervention there early 20c.), "any Pacific Islander" (World War II), "Korean" (1950s), "Vietnamese" and "any Asian" (1960s).
gore (n.1): "thick, clotted blood," Old English gor "dirt, dung, filth, shit," a Germanic word (cognates: Middle Dutch goor "filth, mud;" Old Norse gor "cud;" Old High German gor "animal dung"), of uncertain origin. Sense of "clotted blood" (especially shed in battle) developed by 1560s (gore-blood is from 1550s).
gosling (n.): mid-14c. (late 13c. as a surname), from Old Norse gæslingr, from gos "goose" (see goose (n.)) + diminutive suffix (see -ling). replaced Old English gesling. Or the modern word might be a Middle English formation from gos "goose." Similar formation in Danish gæsling, Swedish gäsling, German Gänslein.
gourmet (n.): "connoisseur in eating and drinking," 1820, from French gourmet, altered (by influence of Middle French gourmant "glutton") from Old French groume, originally "wine-taster, wine merchant's servant" (in 13c. "a lad generally"), a word of uncertain origin. As an adjective from 1900. Compare groom (n.1). For sense distinction, see gourmand.
gout (n.): joint disease, c. 1200, from Old French gote "a drop, bead; the gout, rheumatism" (10c., Modern French goutte), from Latin gutta "a drop," in Medieval Latin "gout," a word of unknown origin. The disease was thought to be caused by drops of viscous humors seeping from the blood into the joints, which turns out to be close to the modern scientific explanation.
graft (n.1): "shoot inserted into another plant," late 15c. alteration of Middle English graff (late 14c.), from Old French graife "grafting knife, carving tool; stylus, pen," from Latin graphium "stylus," from Greek grapheion "stylus," from graphein "to write" (see -graphy). So called probably on resemblance of a stylus to the pencil-shaped shoots used in grafting. The terminal -t- in the English word is not explained. Surgical sense is from 1871.
helicopter (n.): 1861, from French hélicoptère "device for enabling airplanes to rise perpendicularly," thus "flying machine propelled by screws." From Greek helix (genitive helikos) "spiral" (see helix) + pteron "wing" (see ptero-).

The idea was to gain lift from spiral aerofoils, and it didn't work. Used by Jules Verne and the Wright Brothers, the word was transferred to helicopters in the modern sense when those were developed in the 1920s. Nativized in Flemish as wentelwiek "with rotary vanes."
heliotrope (n.): "plant which turns its flowers and leaves to the sun," 1620s, from French héliotrope (14c., Old French eliotrope) and directly from Latin heliotropium, from Greek heliotropion "sundial; heliotropic plant," from helios "sun" (see sol) + tropos "turn" (see trope). In English the word in Latin form was applied c. 1000-1600 to heliotropic plants. Related: Heliotropic.
helix (n.): "a spiral thing," 1560s, originally of the volutes of Corinthian capitals, from Latin helix "spiral, a volute in architecture," from Greek helix (genitive helikos), a word used of anything in a spiral shape (an armlet, a curl of hair, the tendril of a vine, a serpent's coil), which is related to eilein "to turn, twist, roll," from PIE *wel-ik-, from root *wel- (3) "to turn, revolve" (see volvox). The classical plural is helices.
hemp (n.): Old English hænep "hemp, cannabis sativa," from Proto-Germanic *hanapiz (source also of Old Saxon hanap, Old Norse hampr, Old High German hanaf, German Hanf), probably a very early Germanic borrowing of the same Scythian word that became Greek kannabis (see cannabis). As the name of the fiber made from the plant, by c. 1300. Slang sense of "marijuana" dates from 1940s; scientific applications for the narcotic derived from hemp date to 1870.
flotilla (n.): "a small fleet," 1711, from Spanish flotilla, diminutive of flota "a fleet," from flotar "to float," which is said to be from Old French floter "to float, set afloat," which is from a word in Frankish or some other Germanic language corresponding to Old English flood (n.). Compare Old Norse floti "raft; fleet." Sometimes also "a fleet of small ships."
glower (v.): mid-14c., "to shine;" c. 1500, "to stare with wide eyes," perhaps from a Scandinavian source (compare Norwegian dialectal glora "to glow, gleam; stare"), or related to Middle Dutch gluren "to leer;" in either case from Proto-Germanic *glo- (see glow (v.)), root of Old English glowan "to glow," which influenced the spelling of this word. Meaning "to look angrily, look intently and threateningly, scowl" is from 18c. Related: Glowered; glowering. As a noun, 1715, "an angry or threatening stare," from the verb.
glum (adj.): 1540s, "sullen, moody, frowning," from Middle English gloumen (v.) "become dark" (c. 1300), later gloumben "look gloomy or sullen" (late 14c.); see gloom. Or from or influenced by Low German glum "gloomy, troubled, turbid." In English the word was also formerly a noun meaning "a sullen look" (1520s). An 18c. extended or colloquial form glump led to the expression the glumps "a fit of sulkiness." Glunch (1719) was a Scottish variant. Related: Glumly; glumness.
heyday (n.): also hey-day, late 16c. as an exclamation, an alteration of heyda (1520s), an exclamation of playfulness, cheerfulness, or surprise something like Modern English hurrah; apparently it is an extended form of the Middle English interjection hey or hei (see hey). Compare Dutch heidaar, German heida, Danish heida. Modern sense of "stage of greatest vigor" first recorded 1751 (perhaps from a notion that the word was high-day), and it altered the spelling.
hickie (n.): "love bite; mark on skin made by biting or sucking during foreplay or sex," 1934; earlier "pimple, skin lesion" (c. 1915); perhaps a sense extension and spelling variation from the earlier word meaning "small gadget, device; any unspecified object" (1909, see hickey and compare doohickey, still used in this sense).
hickory (n.): type of North American tree valued for its edible nuts and tough, flexible wood, 1670s, American English, from Algonquian (perhaps Powhatan), shortening of pockerchicory, pocohicora or a similar word, which is sometimes said to be the name for this species of walnut, but Bright calls it "a milky drink made from hickory nuts." Old Hickory as the nickname of U.S. politician Andrew Jackson is recorded from 1815.
interjection (n.): early 15c., "an interjected or exclamatory word," from Middle French interjection (Old French interjeccion, 13c.), from Latin interiectionem (nominative interiectio) "a throwing or placing between," also in grammar and rhetoric, noun of action from past participle stem of intericere "to throw between, set between," from inter- "between" (see inter-) + -icere, comb. form of iacere "to throw" (see jet (v.)). Related: Interjectional.
-ent: word-forming element making adjectives from nouns or verbs, from French -ent and directly from Latin -entem (nominative -ens), present participle ending of verbs in -ere/-ire. Old French changed it in many words to -ant, but after c. 1500 some of these in English were changed back to what was supposed to be correct Latin. See -ant.
ento-: word-forming element used chiefly in biology and meaning "within, inside, inner," from Greek ento-, comb. form of entos (adv., prep.) "within, inside," as a noun, "inner parts" (cognate with Latin intus), from PIE *entos-, extended form of root *en "in" (see in), with adverbial suffix *-tos, denoting origin.
entrepreneur (n.): 1828, "manager or promoter of a theatrical production," reborrowing of French entrepreneur "one who undertakes or manages," agent noun from Old French entreprendre "undertake" (see enterprise). The word first crossed the Channel late 15c. (Middle English entreprenour) but did not stay. Meaning "business manager" is from 1852. Related: Entrepreneurship.
envoy (n.): "messenger," 1660s, from French envoyé "messenger; a message; a sending; the postscript of a poem," literally "one sent" (12c.), noun use of past participle of envoyer "send," from Vulgar Latin *inviare "send on one's way," from Latin in "on" (see in- (2)) + via "road" (see via (adv.)). The same French word was borrowed in Middle English as envoi in the sense "stanza of a poem 'sending it off' to find readers" (late 14c.).
maraud (v.): 1690s, from French marauder (17c.), from Middle French maraud "rascal" (15c.), of unknown origin, perhaps from French dialectal maraud "tomcat," echoic of its cry. A word popularized in several languages during the Thirty Years War (Spanish merodear, German marodiren, marodieren "to maraud," marodebruder "straggler, deserter") by punning association with Count Mérode, imperialist general. Related: Marauded; marauding.
marl (n.): "clayey soil used for fertilizer," late 14c., from Old French marle (Modern French marne), from Late Latin marglia, diminutive of Latin marga "marl," which is said by Pliny to be a Gaulish word, but modern Celtic cognates are considered to be borrowed from English or French. As a verb by late 14c. Medieval Latin margila is the source of Dutch mergel, German Mergel.
maroon (n.): "very dark reddish-brown color," 1791, from French couleur marron, the color of a marron "chestnut," the large sweet chestnut of southern Europe (maroon in that sense was used in English from 1590s), from dialect of Lyons, ultimately from a word in a pre-Roman language, perhaps Ligurian; or from Greek maraon "sweet chestnut."
tertium quid (n.): something indeterminate between two other things, 1724, Latin, literally "third something," from tertius "third, a third," from the root of tres "three" (see three). A loan-translation of Greek triton ti (Plato), used in alchemy for "unidentified element present in a combination of two known ones." The Latin word also figures in phrases tertium non datur "no third possibility exists," and tertius gaudens "a third party that benefits from conflict between the other two."
numeral (n.): 1520s, "word expressing a number," from Middle French numéral (late 15c.), from Late Latin numeralis "of or belonging to a number," from Latin numerus "a number" (see number (n.)). Meaning "figure standing for a number" is from 1680s. As an adjective, "expressing number," from 1520s. Old English numerals were formed as in German (seofan and twentig); the modern English pattern likely is from influence of French (vingt-sept).
orotund (adj.): 1792, from Latin ore rotundo "in well-rounded phrases," literally "with round mouth" (see ore rotundo).
The odd thing about the word is that its only currency, at least in its non-technical sense, is among those who should most abhor it, the people of sufficient education to realize its bad formation; it is at once a monstrosity in its form & a pedantry in its use. [Fowler]
ortho-: before vowels orth-, word-forming element meaning "straight, upright, rectangular, regular; true, correct, proper," now mostly in scientific and technical compounds, from Greek ortho-, stem of orthos "straight, true, correct, regular," from PIE *eredh- "high" (source also of Sanskrit urdhvah "high, lofty, steep," Latin arduus "high, steep," Old Irish ard "high").
matins (n.): canonical hour, mid-13c., from Old French matines (12c.), from Late Latin matutinas (nominative matutinæ) "morning prayers," originally matutinas vigilias "morning watches," from Latin matutinus "of or in the morning," associated with Matuta, Roman dawn goddess (see manana). The Old English word was uht-sang, from uhte "daybreak."
mat (adj.): 1640s, "lusterless, dull" (of a color or surface), from French mat "dull, dead surface," from Old French mat "beaten down, withered, afflicted, dejected; dull," which is perhaps from Latin mattus "maudlin with drink," from madere "to be wet or sodden, be drunk," from PIE root *mad- "to be wet, drip" (see mast (n.2)). Or the French word might represent a transferred use from chess of mater "to checkmate, defeat," from Arabic (see mate (v.2)).
Noel (n.): late 14c., nowel "feast of Christmas," from Old French noel "the Christmas season," variant of nael, from Latin natalis (dies) "birth (day)," in Church Latin in reference to the birthday of Christ, from natus, past participle of nasci "be born" (Old Latin gnasci; see genus). The modern word in English, with the sense "a Christmas carol" (1811) probably is a separate borrowing from French. As a masc. proper name, from Old French, probably literally "of or born on Christmas."
Nordic (adj.): 1898, from French nordique (in J. Deniker's system of race classifications), literally "of or pertaining to the north," from nord "north" (a loan-word from Old English; see north). Perhaps influenced by German Nordisch. As a noun, from 1901. Strictly, the blond peoples who inhabit Scandinavia and the north of Britain. As a type of skiing competition, it is attested from 1954.