sea

Etymology

From Middle English see, from Old English sǣ (“sea”), from Proto-West Germanic *saiwi, from Proto-Germanic *saiwiz (compare West Frisian see, Dutch zee, German See, Danish sø, Norwegian Bokmål sjø, Swedish sjö), probably either from Proto-Indo-European *sh₂ey-wo- (“to be fierce, afflict”) (compare Latin saevus (“wild, fierce”), Tocharian B saiwe (“itch”), Latvian sievs, sīvs (“sharp, biting”); more at sore) or derived from *sīhwaną (“to percolate, filter”), in which case *saiwiz is from earlier *saigwiz, Pre-Germanic *soykʷ-ís.

noun

1. A large body of salt water.
   1. The ocean; the continuous body of salt water covering a majority of the Earth's surface.
      At length the universal Wreck appear'd,/ To Cæsar's self, ev'n worthy to be fear'd./ Why all these Pains, this Toil of Fate (he cries)/ This Labour of the Seas, and Earth, and Skies?/ All Nature, and the Gods at once alarm'd,/ Against my little Boat and me are arm'd. 1719, Nicholas Rowe, “Book V”, in Lucan's Pharsalia: Translated into English Verse, Dublin: James Carson, page 183
      There is something in being near the sea, like the confines of eternity. It is a new element, a pure abstraction. The mind loves to hover on that which is endless, and forever the same. People wonder at a steam-boat, the invention of man, managed by man, that makes its liquid path like an iron railway through the sea—I wonder at the sea itself, that vast Leviathan, rolled round the earth, smiling in its sleep, waked into fury, fathomless, boundless, a huge world of water-drops.—Whence is it, whither goes it, is it of eternity, or of nothing? 1833, William Hazlitt, “Notes of a Journey Through France and Italy”, in Greenbank's Periodical Library, volume I, chapter 1, page 173
      As we stood there watching, the long yellow light on the eastern horizon suddenly changed in color—first to a roseate flush, then to a warm crimson; the scenes round us, sky, sea, and land, brightened as if by magic. 1922 March, J. S. Fletcher, “The Mystery of Ravensdene Court”, in Everybody's Magazine, volume XLVI, number 3, page 162
   2. A body of salt water smaller than an ocean, generally forming part of, or connecting with, an ocean or a larger sea.
      The Mediterranean Sea, the Caribbean Sea, the Sea of Crete, etc.
2. A lake, especially if large or if salty or brackish.
   The Caspian Sea, the Sea of Galilee, the Salton Sea, etc.
3. The swell of the sea; a single wave; billow.
   "If they buy three cords of birch logs," said the witch, "but they must be exact measure and no bargaining about the price, and if they throw overboard the one cord of logs, piece by piece, when the first sea comes, and the other cord, piece by piece, when the second sea comes, and the third cord, piece by piece, when the third sea comes, then it's all over with us." 1886, Peter Christen Asbjørnsen, translated by H.L. Brækstad, Folk and Fairy Tales, page 187
   There was a small sea rising with the wind coming up from the east and at noon the old man's left hand was uncramped. 1952, Ernest Hemingway, The Old Man and the Sea
   2020 June 8, National Weather Service Boston, 2:38 PM EDT marine forecast High pressure will maintain light winds and flat seas through Tue night. ... Potential for briefly choppy 3 ft seas near South Coast...
4. (attributive, in combination) Living or used in or on the sea; of, near, or like the sea.
   Seaman, sea gauge, sea monster, sea horse, sea level, seaworthy, seaport, seaboard, etc.
5. (figurative) Anything resembling the vastness or turbulence of the sea.
   To be, or not to be, that is the question,/ Whether tis nobler in the minde to suffer/ The slings and arrowes of outragious fortune,/ Or to take Armes against a sea of troubles,/ And by opposing, end them, to die to sleepe/ No more, and by a sleepe, to say we end/ The hart-ake, and the thousand naturall shocks/ That flesh is heire to. 1604, William Shakespeare, The Tragedie of Hamlet, Prince of Denmarke, London: Nicholas Ling
   Secondly, in terms of geopolitics Central Asia was a huge sea of barbarians set in the midst of interlocking continents. Thanks to its border on the Siberian forest in the north, it was open to barbarian incomers who would upset existing polities and set migrations going. 1980, Patria Crone, Slaves on Horseback: The Evolution of the Islamic Polity, Cambridge University Press
   In the last two decades, North Korea has on various occasions conducted highly provocative missile and nuclear tests and promised to turn Seoul into a sea of fire. April 9, 2013, Andrei Lankov, “Stay Cool. Call North Korea’s Bluff.”, in New York Times
6. (physics) A constant flux of gluons splitting into quarks, which annihilate to produce further gluons.
7. (planetology) A large, dark plain of rock; a mare.
   The Apollo 11 mission landed in the Sea of Tranquility.
8. (planetology) A very large lake of liquid hydrocarbon.