[ oh-shuhn ]
See synonyms for ocean on Thesaurus.com
  1. any part of or the entirety of salt water that covers more than 70 percent of the earth's surface: Most of her adult life had been spent on the ocean, first on a fishing boat, then in the navy, now as a marine biologist.: Compare World Ocean.

  2. any of the geographical divisions of the earth’s salt water, in particular, the five identified as the Pacific, Atlantic, Indian, Southern, and Arctic Oceans.

  1. a vast expanse or quantity: oceans of opportunity;the ocean of people at Woodstock.

Origin of ocean

First recorded in 1250–1300; Middle English ocean(e), from Old French or directly from Latin ōceanus, special use of Ōceanus Oceanus, from Greek ōkeanós, Ōkeanós

Other words from ocean

  • o·cean·like, adjective
  • in·ter·o·cean, adjective

Words Nearby ocean

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How to use ocean in a sentence

British Dictionary definitions for ocean


/ (ˈəʊʃən) /

  1. a very large stretch of sea, esp one of the five oceans of the world, the Atlantic, Pacific, Indian, Arctic, and Antarctic

  2. the body of salt water covering approximately 70 per cent of the earth's surface

  1. a huge quantity or expanse: an ocean of replies

  2. literary the sea

Origin of ocean

C13: via Old French from Latin ōceanus, from Greek ōkeanos Oceanus

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for ocean


[ ōshən ]

  1. The continuous body of salt water that covers 72 percent of the Earth's surface. The average salinity of ocean water is approximately three percent. The deepest known area of the ocean, at 11,034 m (36,192 ft) is the Mariana Trench, located in the western Pacific Ocean.

  2. Any of the principal divisions of this body of water, including the Atlantic, Pacific, Indian, and Arctic Oceans.

usage For ocean

The word ocean refers to one of the Earth's four distinct, large areas of salt water, the Pacific, Atlantic, Indian, and Arctic Oceans. The word can also mean the entire network of water that covers almost three quarters of our planet. It comes from the Greek Okeanos, a river believed to circle the globe. The word sea can also mean the vast ocean covering most of the world. But it more commonly refers to large landlocked or almost landlocked salty waters smaller than the great oceans, such as the Mediterranean Sea or the Bering Sea. Sailors have long referred to all the world's waters as the seven seas. Although the origin of this phrase is not known for certain, many people believe it referred to the Red Sea, the Mediterranean Sea, the Persian Gulf, the Black Sea, the Adriatic Sea, the Caspian Sea, and the Indian Ocean, which were the waters of primary interest to Europeans before Columbus.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.