ocean

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The entire body of salt water that covers more than 70 percent of the earth's surface.
2. n. Any of the principal divisions of the ocean, including the Atlantic, Pacific, Indian, Arctic, and Antarctic oceans.
3. n. A great expanse or amount: "that ocean of land which is Russia” ( Henry A. Kissinger).

Century Dictionary and Cyclopedia

1. n. The body of water which envelops the earth, and covers almost three fourths of its surface with a mean depth — as nearly as can be estimated at the present time — of less than 12,500 feet. Physical geographers, following the lead of the Royal Geographical Society, generally divide the entire oceanic area into five distinct oceans, namely the Arctic, Antarctic, Atlantic, Pacific, and Indian; but these divisions are largely artificial, the lines by which they are indicated being in no small part parallels and meridians. The Arctic and Antarctic oceans, according to this scheme, extend from the north and south poles respectively to the arctic and antarctic circles. The Atlantic extends between the two polar circles, being limited on the east by the land-masses of Europe and Africa and by the meridian extending from Cape Agulhas to the antarctic circle, and on the west by the American land-mass and the meridian of Cape Horn. The Pacific has as its land-limits on the cast the American coast, and on the west the Asiatic land-mass, the Philippine Islands, New Guinea, and Australia; its imaginary limits are the meridians of Cape Horn and the South Cape of Tasmania prolonged to meet the antarctic circle. The Indian ocean extends south from the Asiatic mainland to the antarctic circle, its eastern and western imaginary limits having been already given in defining those of the Pacific and Atlantic. Thus, as will be noticed, there are no natural limits on the south of either the Atlantic, the Pacific, or the Indian ocean, since these all unite with the Antarctic ocean to form one continuous area of water. Hence it would be more philosophical to call the vast area of water occupying the chief part of the southern hemisphere the Southern ocean, as has been done by Herschel and Thomson, and to consider the Atlantic, Pacific, and Indian oceans as immense gulfs or prolongations toward the north of the still greater Southern ocean. The Pacific ocean was most generally designated by the older English navigators as the “South Sea,” and this name is still current among the Germans. The Atlantic and Pacific are also generally divided into North and South Atlantic and North and South Pacific by the equatorial line. The smaller divisions of the ocean are, in the order of their respective magnitudes, seas, gulfs, bays, sounds, straits, coves, holes, and harbors (see each of these words). The mean depth of the ocean is probably not far from six times the mean elevation of the land above the ocean-level. The deepest soundings of the ocean, however, give figures a little inferior in amount to those indicating the elevation of the very highest mountain-summits. In several different parts of the ocean depths of over 26,000 feet have been sounded, but nowhere as yet has a depth as great as 29,000 feet (the height of Gaurisankar) been reached. (See deep-sea sounding-machine, under deepsea.) The oceanic currents are of great importance in their effect on climate. The principal surface current is the equatorial, due to the action of the trade winds, by which the water is continually nrged westward, but, being driven in its westerly course against the land-masses, it is deflected by them, and forced to perform an immense gyration by which it returns into the general system far to the eastward. Owing to the shape of the land-masses in the northern hemisphere, these modifications of the equatorial current are much more distinct and important than they are to the south of the equator. Two of the oceanic currents are especially interesting, the Gulf Stream of the Atlantic and the Kuroshiwo of the Pacific (see these terms). The surface temperature of the ocean varies greatly in the different latitudes and with the strength and direction of the surface currents, the Gulf Stream playing a most important part in ameliorating the climate of northwestern Europe by means of the heated surface water which it carries from the equatorial regions. Besides these surface currents, however, there is a general exchange of water always going on in the depths of the ocean between the warmer equatorial and the colder polar waters, brought about by the difference in specific gravity of the two. As the result of this, it is found that the temperature of the ocean as a rule diminishes as greater depths are attained, and that the deeper parts, where open to the general circulation, are near the freezing-point. A remarkable feature of the ocean-water is the uniformity in the nature and quality of the salts which it contains, provided the specimen has been taken at considerable distance from land. The weight of the salts held in solution by the main ocean is about 3½ per cent. of the whole; of this about three quarters is common salt, one tenth chlorid of magnesium, one twentieth sulphate of magnesia, about the same sulphate of lime, one twenty-fifth chlorid of potassium, and a little over one per cent. bromide of sodium. Other substances are also present in smaller quantity, making in all about twenty-nine elements which have been detected in the ocean-water; many of these, however, exist only in very minute traces. The economical value of the ocean as a source of supply for common salt is considerable; but the quantity thus obtained is not so great as that furnished by mines of rock-salt or by the evaporation of brine got by boring. See salt.
2. n. Something likened to the ocean; also, a great quantity: as, an ocean of trouble.
3. Of or pertaining to the main or great sea.

Wiktionary

1. n. countable One of the five large bodies of water separating the continents.
2. n. uncountable Water belonging to an ocean.
3. n. figuratively An immense expanse; any vast space or quantity without apparent limits.

GNU Webster's 1913

1. n. The whole body of salt water which covers more than three fifths of the surface of the globe; -- called also the sea, or great sea.
2. n. One of the large bodies of water into which the great ocean is regarded as divided, as the Atlantic, Pacific, Indian, Arctic and Antarctic oceans.
3. n. An immense expanse; any vast space or quantity without apparent limits
4. adj. Of or pertaining to the main or great sea

WordNet 3.0

1. n. anything apparently limitless in quantity or volume
2. n. a large body of water constituting a principal part of the hydrosphere