Online Etymology Dictionary

ocean: late 13c., from O.Fr. occean (12c.), from L. oceanus, from Gk. okeanos, the great river or sea surrounding the disk of the Earth (as opposed to the Mediterranean), of unknown origin. Personified as Oceanus, son of Uranus and Gaia and husband of Tethys. In early times, when the only known land masses were Eurasia and Africa, the ocean was an endless river that flowed around them. Until c.1650, commonly ocean sea, translating L. mare oceanum. Application to individual bodies of water began 14c.; there are usually reckoned to be five of them, but this is arbitrary; also occasionally applied to smaller subdivisions, e.g. German Ocean "North Sea."
oceanography: coined in English, 1859, from ocean + Gk. -graphia "description," from graphein "to write" (about).
oceanic: 1650s, from Mod.L. oceanicus, from L. oceanus (see ocean).
abyssal: 1690s, used especially of the zone of ocean water below 300 fathoms, from abyss.
breaker: "heavy ocean wave," 1680s, agent noun from break. Related: Breakers.
pond: 1248, "artificially banked body of water," variant of pound "enclosed place" (see pound (n.2)). Jocular reference to "the Atlantic Ocean" dates from 1641.
briny (adj.): c.1600, from brine + -y (2). Used earlier of tears than of the ocean (1610s).
Pacific Ocean: 1660, from M.L. Pacificum, neut. of L. pacificus (see pacific); so called c.1500 by Magellan when he sailed into it and found it calmer than the stormy Atlantic.
dateline: 1880, imaginary line down the Pacific Ocean on which the calendar day begins and ends, from date + line. Meaning "line of text that tells the date and place of origin of a newspaper, article, telegram, etc." is from 1888.
trans-oceanic: 1827, "situated across the ocean," from trans- + oceanic. Meaning "passing over the sea" is recorded from 1868.
Pegasus: winged horse in Gk. mythology, late 14c., from L., from Gk. Pegasos, usually said to be from pege "spring, font" (pl. pegai), especially in "springs of Ocean," near which Medusa was said to have been killed by Perseus (Pegasus sprang from her blood). But this may be folk etymology, and the suffix -asos suggests a pre-Gk. origin.
monsoon: "trade wind of the Indian Ocean," 1584, from Du. monssoen, from Port. monçao, from Ar. mawsim "appropriate season" (for a voyage, pilgrimage, etc.), from wasama "he marked." When it blows from the southwest (April through October) it brings heavy rain, hence "the rainy season" (1747).
tidal: 1807, a hybrid formation from tide (q.v.) + Latin-derived suffix -al. A tidal wave (1830) is properly high water caused by movements of the tides; erroneous use for "tsunami, great ocean wave caused by an earthquake, etc." is recorded from 1878.
Cimmerian: "pertaining to the Cimmerii, an ancient nomadic people who, according to Herodotus, inhabited the region around the Crimea, and who, according to Assyrian sources, overran Asia Minor 7c. B.C.E., from L. Cimmerius, from Gk. Kimmerios. Homer described their land as a place of perpetual mist and darkness beyond the ocean, but whether he had in mind the same people Herodotus did, or any real place, is unclear.
shuffleboard: 1530s, shovillaborde "shovel board," an unexplained alteration of shove-board (1520s), from shove + board (n.). Originally a tabletop game (c.1600), the large-scale version (1877) was invented for play on ocean liners.
forty: O.E. feowertig, from feower "four" + tig "group of ten" (see -ty (1)). Roaring Forties are rough parts of the ocean between 40 and 50 degrees latitude. Forty winks "short sleep" is attested from 1828.
Atlantic: late 14c., occean of athlant "sea off the west coast of Africa," from L. Atlanticus, from Gk. Atlantikos, adjectival form of Atlas (gen. Atlantos), in ref. to Mount Atlas in Mauritania (see Atlas). Applied to the whole ocean since c.1600.
fortunate: late 14c., L. fortunatus, from fortunare, from fortuna (see fortune). Related: Fortunately. Fortunate Islands "mythical abode of the blessed dead, in the Western Ocean," early 15c., translates L. Fortunatae Insulae.
benthos: "life forms of the deep ocean and sea floor," 1891, coined by Haeckel from Gk. benthos "depth of the sea," related to bathos "depth," bathys "deep." Adjective benthic is attested from 1902.
holm: from O.N. holmr "small island, especially in a bay or river," also "meadow by a shore," or cognate O.Dan. hulm "low lying land," from P.Gmc. *hul-maz, from PIE base *kel- "to rise, be elevated" (see hill). Obsolete, but preserved in place names. Cognate O.E. holm (only attested in poetic language) meant "sea, ocean, wave."
North Sea: in O.E., this meant the Bristol Channel. The application to the body of water presently so named is from Du. It lies to the north of Holland, where it and was contrasted with the inland Zuider Zee (lit. "Southern Sea"). To the Danes, it sometimes was Vesterhavet "West Sea." In Eng., this had been typically called the "German Sea" or "German Ocean," which follows the Roman name for it, Oceanus Germanicus. First transf. use of North Sea from Du. is from late 13c., though "German" persisted on some maps at least into the 1830s.
amok: in phrase to run amok first recorded 1670s, from Malay amuk "attacking furiously." Earlier the word was used as a noun or adj. meaning "a frenzied Malay," originally in the Port. form amouco or amuco.
"There are some of them [the Javanese] who ... go out into the streets, and kill as many persons as they meet. ... These are called Amuco." ["The Book of Duarte Barbosa: An Account of the Countries Bordering on the Indian Ocean and Their Inhabitants," c.1516, Eng. transl.]
Cf. amuck.
Dead Sea: mid-13c., from dead + sea; its water is 26 percent salt (as opposed to 3 or 4 percent in most oceans) and supports practically no life. In the Bible it was the "Salt Sea" (Heb. yam hammelah), also "Sea of the Plain" and "East Sea." In Arabic it is al-bahr al-mayyit "Dead Sea." The ancient Greeks knew it as he Thalassa asphaltites "the Asphaltite Sea." Latin Mare Mortum, Gk. he nekra thalassa (both "The Dead Sea") referred to the sea at the northern boundaries of Europe, the Arctic Ocean.
deck (n.): mid-15c., probably aphetic of M.L.G. verdeck, a nautical word, from ver- "fore" + decken "to cover, put under roof," from P.Gmc. *thackjam (related to thatch), from PIE *(s)tog-/*(s)teg- "cover" (see stegosaurus). Sense extended early in English from "covering" to "platform of a ship." "Pack of cards" is 1590s, perhaps because they were stacked like decks of a ship. The verb sense of "knock down" is first recorded c.1953, probably from notion of laying someone out on the deck. Deck chair (1884) so called because they were used on ocean liners. Tape deck (1949) is in ref. to the flat surface of old reel-to-reel tape recorders.
south: O.E. suð "southward, in the south," from P.Gmc. *sunthaz (cf. O.S., O.Fris. suth "southward, in the south," M.Du. suut), perhaps related to base of *sunnon "sun," with sense of "the region of the sun." Ger. Süd, Süden are from a Du. pronunciation. O.Fr. sur, sud (Fr. sud), Sp. sur, sud are loan-words from Gmc., perhaps from O.N. suðr. The Southern states of the U.S. have been collectively called The South since 1779 (though originally this often refered only to Georgia and South Carolina). South country in Britain means the part below the Tweed, in England the part below the Wash, and in Scotland the part below the Forth. The nautical coat called a sou'wester (1836) protects the wearer against severe weather, such as a gale out of the southwest. South Sea meant "the Mediterranean" (late 14c.) and "the English Channel" (early 15c.) before it came to mean (in pl.) "the South Pacific Ocean" (1520s).
taboo: 1777 (in Cook's "A Voyage to the Pacific Ocean"), "consecrated, inviolable, forbidden, unclean or cursed," explained in some Englishsources as being from Tongan (Polynesian language of the island of Tonga) ta-bu "sacred," from ta "mark" + bu "especially." But this may be folk etymology, as linguists in the Pacific have reconstructed an irreducable Proto-Polynesian *tapu, from Proto-Oceanic *tabu "sacred, forbidden" (cf. Hawaiian kapu "taboo, prohibition, sacred, holy, consecrated;" Tahitian tapu "restriction, sacred;" Maori tapu "be under ritual restriction, prohibited"). The noun and verb are Eng. innovations first recorded in Cook's book.