ocean

noun

ˈō-shən 

plural oceans

often attributive

1

a

: the whole body of salt water that covers nearly three fourths of the surface of the earth

The ocean covers most of our planet, regulates our weather and climate, absorbs vast amounts of carbon dioxide, provides most of our oxygen, and feeds much of the human population.

—National Oceanic and Atmospheric Administration

b

: any of the large bodies of water into which the mass of salt water covering most of the earth is divided

the oceans of the world

2

: a very large or unlimited quantity or expanse

Could have made oceans of money.

—James Joyce

He would have oceans of time for his ride.

—P. G. Wodehouse

Jutting from an ocean of prairie, they [the Sangre de Cristo mountains] run north-south like an iguana spine …

—Skiing

Synonyms of ocean

• sea

Examples of ocean in a Sentence

We've sailed across hundreds of miles of ocean.

the Pacific and Indian oceans

Recent Examples on the Web

Some of the ocean’s most powerful predators are warm-blooded creatures that burn nearly four times more energy than their cold-blooded counterparts. —Maria Mocerino, Interesting Engineering, 19 Apr. 2026

The two side boosters returned for a land landing at Landing Zones 1 and 2 at Cape Canaveral Space Force Station while the center core stage fell into the ocean. —Richard Tribou, The Orlando Sentinel, 19 Apr. 2026

Three sets of newlyweds have disappeared from a Florida resort, their bruised and broken bodies washing up on the ocean shore. —Sandra Dallas, Denver Post, 19 Apr. 2026

The Jonathan Stout Orchestra, featuring Hilary Alexander, performed for the crowd, the ocean just steps away. —Laylan Connelly, Oc Register, 19 Apr. 2026

Word History

Etymology

Middle English occean "the sea flowing around the land mass of the known world," borrowed from Anglo-French, borrowed from Latin Ōceanus, borrowed from Greek Ōkeanós, probably of pre-Greek substratal origin

Note: Preserved variants of Greek Ōkeanós, as Ōgḗn, Ōgenós, Ōgēnós, may indicate that the velar stop, whatever its original voicing, was palatalized (hence *ūkʸān-?)—strongly suggesting non-Indo-European origin. Old attempts to find an Indo-European origin (as a comparison with Sanskrit ā-śayāna- "lying on") are unconvincing.

First Known Use

14th century, in the meaning defined at sense 1a

Phrases Containing ocean

• a drop in the ocean
• inter-ocean
• mid-ocean ridge
• ocean perch
• ocean sunfish
• open ocean

Rhymes for ocean

• lotion
• notion
• potion
• commotion
• demotion
• devotion
• emotion
• laotian
• promotion
• locomotion

Kids Definition

ocean

noun

ˈō-shən 

1

: the whole body of salt water that covers nearly three fourths of the surface of the earth

2

: one of the large bodies of water into which the ocean is divided

oceanic

ˌō-shē-ˈan-ik

adjective