sea

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The continuous body of salt water covering most of the earth's surface, especially this body regarded as a geophysical entity distinct from earth and sky.
2. n. A tract of water within an ocean.
3. n. A relatively large body of salt water completely or partially enclosed by land.
4. n. A relatively large landlocked body of fresh water.
5. n. The condition of the ocean's surface with regard to its course, flow, swell, or turbulence: a rising sea; choppy seas.
6. n. A wave or swell, especially a large one: a 40-foot sea that broke over the stern.
7. n. Something that suggests the ocean in its overwhelming sweep or vastness: a sea of controversy.
8. n. Seafaring as a way of life.
9. n. Astronomy A lunar mare.
10. idiom. at sea On the sea, especially on a sea voyage.
11. idiom. at sea In a state of confusion or perplexity; at a loss.

Century Dictionary and Cyclopedia

1. n. The salt waters that cover the greater part of the earth's surface; the ocean. [The word sea in compound words always has the meaning of ‘ocean.’ In this sense, with a hyphen, the word is the first element of numerous names, especially of animals and plants, the more noteworthy of which are entered in the following columns.]
2. n. A great body of salt water; a more or less distinctly limited or landlocked part of the ocean having considerable dimensions. Such seas are frequently limited or separated from each other by linear groups of islands; this is especially the case on the Pacific coast of Asia, and in the East Indies, where there are more seas in this sense than anywhere else. Smaller areas thus more or less completely inclosed by land are known as bays, gulfs, sounds, etc. Thus, we speak of the Mediterranean Sea and, as a smaller division of this, the Adriatic Sea; but of the Gulf of Taranto, and the Bay of Naples. The name sea is not now usually given to entirely landlocked sheets of water—such use being either traditional, as in the Dead Sea, Sea of Galilee, or exceptional, as in the Caspian Sea, Sea of Aral. Sea, bay, and gulf are more or less synonymous terms. Thus, the Arabian Sea and the Bay of Bengal do not differ essentially in the extent to which they are landlocked; the same may be said of the Gulf of Mexico and the Caribbean Sea; and Hudson's Bay might equally well, or even more properly, be called Hudson Sea.
3. n. Any widely extended or overwhelming mass or quantity; an ocean; a flood: as, a sea of difficulties; a sea of upturned faces.
4. n. The swell of the ocean, or the direction of the waves: as, there was a heavy sea on; to keep the boat's head to the sea.
5. n. A large wave; a billow; a surge: as, to ship a sea.
6. n. Out on the ocean, and out of sight of land; hence, in the condition of a mariner who has lost his bearings; in a state of uncertainty or error; astray; wide of the mark; quite wrong: as, you are altogether at sea in your guesses.
7. n. By the margin of the sea; on the sea-coast.
8. n. An obsolete spelling of see.

Wiktionary

1. n. A large body of salty water. (Major seas are known as oceans.)
2. n. figuratively A large number or quantity; a vast amount.

GNU Webster's 1913

1. n. One of the larger bodies of salt water, less than an ocean, found on the earth's surface; a body of salt water of second rank, generally forming part of, or connecting with, an ocean or a larger sea.
2. n. An inland body of water, esp. if large or if salt or brackish; ; sometimes, a small fresh-water lake.
3. n. The ocean; the whole body of the salt water which covers a large part of the globe.
4. n. The swell of the ocean or other body of water in a high wind; motion or agitation of the water's surface; also, a single wave; a billow.
5. n. (Jewish Antiq.) A great brazen laver in the temple at Jerusalem; -- so called from its size.
6. n. Fig.: Anything resembling the sea in vastness.

WordNet 3.0

1. n. anything apparently limitless in quantity or volume
2. n. turbulent water with swells of considerable size
3. n. a division of an ocean or a large body of salt water partially enclosed by land