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 great ocean 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

• blue
• brine
• deep
• Neptune
• sea
• seven seas

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

Our goal is to explain the journey and the importance of ocean literacy and education. —Martino Carrera, Footwear News, 10 June 2025

Step Back The mission and long-term plan behind AIM is to address the impacts of climate change, specifically by building seawalls that can protect coastal areas from rising ocean levels, Sadilek said. —Rachyl Jones, semafor.com, 10 June 2025

It was supported by more than 4,400 pilings — 70-foot Douglas fir beams driven about 20 feet into the ocean floor. —Hailey Branson-Potts, Los Angeles Times, 8 June 2025

The region gets its name from the fleet of Spanish ships wrecked off the coast in the 1700s, leaving gold and silver coins strewn across the ocean floor. —Kelsey Glennon, Southern Living, 8 June 2025

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