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

[Middle English occean, from Old French, from Latin ōceanus, from Greek Ōkeanos, the god Oceanus, a great river encircling the earth.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.