Online Etymology Dictionary

scuba: 1952, acronym for self-contained underwater breathing apparatus.
scud (v.): "to move quickly," 1530s, of uncertain origin, perhaps a variant of Middle English scut "rabbit, rabbit's tail," in reference to its movements (see scut (n.1)), but there are phonetic difficulties. Perhaps rather from a North Sea Germanic source akin to Middle Low German, Middle Dutch schudden "to shake" (see quash). Related: Scudded; scudding. As a noun from c. 1600, from the verb. It also was the NATO reporting name for a type of Soviet missile introduced in the 1960s.
scudo (n.): old Italian silver coin, Italian, literally "shield" (in reference to the device it bore), from Latin scutum (see hide (n.1)).
scuff (v.): 1768, "to walk (through or over something) without raising the feet," from Scottish, probably from a Scandinavian source related to Old Norse skufa, skyfa "to shove, push aside," from PIE *skeubh- "to shove" (see shove (v.)). Meaning "injure the surface of" is from 1897. Related: Scuffed; scuffing. As a noun from 1824.
scuffle (v.): "to push or fight in a disorderly manner," 1570s, probably a frequentative form of scuff, of Scandinavian origin. Related: Scuffled; scuffling. As a noun c. 1600, from the verb.
scull (n.): kind of short, light, spoon-bladed oar, mid-14c., of unknown origin. The verb is from 1620s, from the noun. Related: Sculled; sculling.
scullery (n.): mid-15c. (early 14c. as a surname), "household department concerned with the care of kitchen utensils," from Old French escuelerie "office of the servant in charge of plates, etc.," from escuelier "keeper of the dishes," from escuele "dish" (12c., Modern French écuelle), from Latin scutella "serving platter, silver" (see scuttle (n.)).
scullion (n.): "low-ranking domestic servant who performs menial kitchen tasks," late 15c., perhaps from Middle French escouillon "a swab, cloth," diminutive of escouve "broom, twig," from Latin scopa (plural scopæ) "broom," related to scapus "shaft, stem" (see scape (n.2)). Or an alteration of Old French souillon "scullion," by influence of scullery.
sculpt (v.): 1826 (implied in sculpted), from French sculpter, from Latin sculpt-, past participle stem of sculpere "to carve" (see sculpture). Related: Sculpting. The older verb form was sculpture (1640s), also sculp (1530s).
sculptor (n.): 1630s, from Latin sculptor "one who cuts or carves," agent noun from sculpt-, past participle stem of sculpere "to carve" (see sculpture). Fem. form sculptress attested from 1660s.
sculpture (n.): late 14c., from Latin sculptura "sculpture," from past participle stem of sculpere "to carve, engrave," back-formation from compounds such as exculpere, from scalpere "to carve, cut," from PIE root *(s)kel- (1) "to cut, cleave" (see scale (n.1)).
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).
scumbag (n.): "condom," by 1939, slang, from scum + bag (n.). Earlier (by 1817) it was used in sugar refining as the name of a frame covered in coarse cloth used in straining. Meaning "despicable person" is attested by 1971.
scummy (adj.): 1570s, from scum + -y (2). Transferred sense of "filthy, disreputable" is recorded from 1932. Related: Scumminess.
scupper (n.): "opening in a ship's side at deck level to let the water flow out," early 15c., perhaps from Old French escopir "to spit out," or related to Dutch schop "shovel," or from Middle English scope "scoop" (see scoop (n.)).
scuppernong (n.): cultivated muscadine grape vine, 1811, from name of a river in North Carolina, U.S., recorded 18c. as Cascoponung, Cuscopang, from an unidentified American Indian word.
scurf (n.): late Old English sceorf, from Proto-Germanic *skurf- (source also of Danish skurv, Middle Dutch scorf, Dutch schurft, Old High German scorf, German Schorf "scurf"), probably related to Old English sceorfan "to gnaw," scearfian "to cut into shreds," from PIE *skerp-, from root *(s)ker- "to cut" (see shear (v.)).
scurfy (adj.): late 15c., from scurf + -y (2). Compare scurvy. Related: Scurfiness.
scurrility (n.): c. 1500, from Latin scurrilitas "buffoonery," from scurrilis (see scurrilous).
scurrilous (adj.): "using such language as only the licence of a buffoon can warrant" [Johnson], 1570s, from scurrile "coarsely joking" (c. 1500, implied in scurrility), from Latin scurrilis "buffoonlike," from scurra "fashionable city idler, man-about-town," later "buffoon." According to Klein, "an Etruscan loan-word." Related: Scurrilously; scurrilousness.
scurry (v.): 1810, perhaps from hurry-scurry (1732), a reduplication of hurry (v.). As a noun, 1823, from the verb.
scurvy (n.): 1560s, noun use of adjective scurvy "covered with scabs, diseased, scorbutic" (early 15c.), variant of scurfy. It took on the narrower meaning of Dutch scheurbuik, French scorbut "scurvy," in reference to the disease characterized by swollen and bleeding gums, prostration, etc., perhaps from Old Norse skyrbjugr, which is perhaps literally "a swelling (bjugr) from drinking sour milk (skyr) on long sea voyages;" but OED has alternative etymology of Middle Dutch or Middle Low German origin, as "disease that lacerates the belly," from schoren "to lacerate" + Middle Low German buk, Dutch buik "belly."
scuse (v.): shortened form of excuse (v.), attested from late 15c.
scut (n.2): term of contempt for a person, 1873, of unknown origin.
scut (n.1): "short, erect tail" (of a rabbit, hare, deer, etc.), 1520s; earlier "a hare" (mid-15c.), perhaps from Old Norse skjota "to shoot (with a weapon), launch, push, shove quickly" (compare Norwegian skudda "to shove, push"), from PIE *skeud- "to shoot, chase, throw" (see shoot (v.)).
scutcheon (n.): mid-14c., short for escutcheon.
scuttle (n.): "bucket," late Old English scutel "dish, platter," from Latin scutella "serving platter" (source also of French écuelle, Spanish escudilla, Italian scudella "a plate, bowl"), diminutive of scutra "flat tray, dish," perhaps related to scutum "shield" (see hide (n.1)).

A common Germanic borrowing from Latin (Old Norse skutill, Middle Dutch schotel, Old High German scuzzila, German Schüssel "a dish"). Meaning "basket for sifting grain" is attested from mid-14c.; sense of "bucket for holding coal" first recorded 1849.
scuttle (v.1): "scamper, scurry," mid-15c., probably related to scud (v.). Related: Scuttled; scuttling.
I should have been a pair of ragged claws
Scuttling across the floors of silent seas.
[T.S. Eliot, "The Love Song of J. Alfred Prufrock"]
scuttle (v.2): "cut a hole in a ship to sink it," 1640s, from skottell (n.) "opening in a ship's deck" (late 15c.), from Middle French escoutille (Modern French écoutille) or directly from Spanish escotilla "hatchway," diminutive of escota "opening in a garment," from escotar "cut out," perhaps from e- "out" (see ex-) + Germanic *skaut-. Figurative use is recorded from 1888. Related: Scuttled; scuttling.
scuttlebutt (n.): 1805, "cask of drinking water kept on a ship's deck, having a hole (scuttle) cut in it for a cup or dipper," from scuttle "opening in a ship's deck" (see scuttle (v.2)) + butt (n.2) "barrel." Earlier scuttle cask (1777). Meaning "rumor, gossip" first recorded 1901, originally nautical slang, traditionally said to be from the sailors' custom of gathering around the scuttlebutt to gossip. Compare water-cooler, figurative for "workplace gossip" mid-20c.
scuzzy (adj.): 1968, North American colloquial, perhaps a blend of scummy and fuzzy [Barnhart]. First attested use is in reference to Ratso Rizzo in "Midnight Cowboy."
Scylla (n.): sea-monster in the Strait of Messina, from Latinized form of Greek Skylla, of unknown origin, perhaps related to skyllein "to tear."
scythe (n.): Old English siðe, sigði, from Proto-Germanic *segithoz (source also of Middle Low German segede, Middle Dutch sichte, Old High German segensa, German Sense), from PIE root *sek- "to cut" (see section (n.)). The sc- spelling crept in early 15c., from influence of Latin scissor "carver, cutter" and scindere "to cut." Compare French scier "saw," a false spelling from sier.
scythe (v.): 1570s, "use a scythe;" 1590s "to mow;" from scythe (n.). From 1897 as "move with the sweeping motion of a scythe." Related: Scythed; scything.
Scythian (n.): 1540s, from Latin Scythia, from Greek Skythia, name anciently given to the region along the north coast of the Black Sea, from Skythes "a Scythian," said to be from an Indo-European root meaning "shepherd" [Room]. As an adjective from 1560s. Herodotus is responsible for Scythian disease or Scythian insanity.
se-: word-forming element, from Latin se-, collateral form of sed- "without, apart, aside, on one's own," related to sed, Latin reflexive pronoun (accusative and ablative), from PIE *sed-, extended form of root *s(w)e-, pronoun of the third person and reflexive (source also of German sich; see idiom).
sea (n.): Old English sæ "sheet of water, sea, lake, pool," from Proto-Germanic *saiwaz (source also of Old Saxon seo, Old Frisian se, Middle Dutch see, Swedish sjö), of unknown origin, outside connections "wholly doubtful" [Buck]. Meaning "large quantity" (of anything) is from c. 1200. Meaning "dark area of the moon's surface" is attested from 1660s (see mare (n.2)).

Germanic languages also use the general Indo-European word (represented by English mere (n.)), but have no firm distinction between "sea" and "lake," either by size, by inland or open, or by salt vs. fresh. This may reflect the Baltic geography where the languages are thought to have originated. The two words are used more or less interchangeably in Germanic, and exist in opposite senses (such as Gothic saiws "lake," marei "sea;" but Dutch zee "sea," meer "lake"). Compare also Old Norse sær "sea," but Danish sø, usually "lake" but "sea" in phrases. German See is "sea" (fem.) or "lake" (masc.). The single Old English word sæ glosses Latin mare, aequor, pontus, pelagus, and marmor.

Phrase sea change "transformation" is attested from 1610, first in Shakespeare ("The Tempest," I.ii). Sea anemone is from 1742; sea legs is from 1712; sea level from 1806; sea urchin from 1590s. At sea in the figurative sense of "perplexed" is attested from 1768, from literal sense of "out of sight of land" (c. 1300).
sea monkey (n.): 1909 as a heraldic animal, 1964 as a U.S. proprietary name for brine shrimp (Artemia salina), which had been used as food for aquarium fish till they began to be marketed as pets by U.S. inventor Harold von Braunhut (d.2003), who also invented "X-Ray Specs" and popularized pet hermit crabs. He began marketing them in comic book advertisements in 1960 as "Instant Life," and changed the name to Sea Monkeys in 1964, so called for their long tails.
sea-breeze (n.): one blowing from the sea to the shore, 1690s, from sea + breeze (n.).
sea-dog (n.): 1590s, "harbor seal," from sea + dog (n.). Also "pirate" (1650s). Meaning "old seaman, sailor who has been long afloat" is attested from 1840.
sea-floor (n.): 1832, from sea + floor (n.).
sea-green (n.): as a color, 1590s, from sea + green (adj.). As an adjective from c. 1600.
sea-horse (n.): late 15c., "walrus," from sea + horse (n.); also see walrus. Also in heraldry as a fabulous animal with the foreparts of a horse and the tail of a fish. Main modern sense in zoology is attested from 1580s.
sea-lion (n.): c. 1600, "kind of lobster," from sea + lion. Later the name of a fabulous animal (in heraldry, etc.), 1660s. Applied from 1690s to various species of large eared seals. As code name for the planned German invasion of Britain, it translates German Seelöwe, announced by Hitler July 1940, scrubbed October 1940.
sea-monster (n.): 1580s, from sea + monster. Sea serpent is attested from 1640s. In Old English a sea-monster might be called sædraca "sea dragon," or sædeor.
sea-salt (n.): c. 1600, from sea + salt (n.).
Seabee (n.): 1942, from pronunciation of C.B., abbreviation of Construction Battalion, formed as a volunteer branch of the Civil Engineer Corps of the U.S. Navy.
seaboard (n.): "seaward side of a ship," late 15c., from sea + board (n.2).
seacoal (n.): also sea-coal, old name for "mineral coal" (as opposed to charcoal), mid-13c.; earlier, in Old English, it meant "jet," which chiefly was found washed ashore by the sea. The coal perhaps so called from resemblance to jet, or because it was first dug from beds exposed by wave erosion. From sea + coal. As it became the predominant type used, the prefix was dropped.
seafarer (n.): 1510s, from sea + agent noun from fare (n.). The Anglo-Saxon poem known by this name since at least 1842 was untitled in original MS.