ocean

ocean — noun

1. the huge stretch of salty water wrapping around our planet, or any wide expanse

1.nounA2
Definition

the huge stretch of salty water wrapping around our planet, or any wide expanse of it far from shore.

Example

Maya stood on the cliff and watched the ocean crash against the dark rocks below.

the ocean as scenic backdrop

Plastic bottles and old fishing nets are slowly choking the ocean.

common environmental collocation

Common collocations
  • open ocean
  • deep ocean
  • ocean floor
  • ocean current
  • swim in the ocean
Synonyms
  • sea

    everyday word for the same body of water; preferred in British English

  • the deep

    literary or poetic, suggesting mystery and danger

  • the briny

    informal British, often humorous

Antonyms
  • land

    the dry surface, opposite of the watery one

Grammar Patterns

the ocean

in/across/under the ocean

Usage Note

Almost always takes the definite article: 'the ocean'. American English uses 'the ocean' where British English often says 'the sea' for the same idea.

Common Mistakes

I love swim in ocean.
I love swimming in the ocean.
needs 'the' before 'ocean' and the -ing form after 'love'.
We went to ocean last weekend.
We went to the ocean last weekend.
drop the article only with proper names like 'Pacific Ocean'.

2. any of the five separately named saltwater regions on Earth — Pacific, Atlantic,

2.nounA2
Definition

any of the five separately named saltwater regions on Earth — Pacific, Atlantic, Indian, Southern, or Arctic — each treated as a distinct geographical area.

Example

The Pacific Ocean is the largest of the five oceans on Earth.

proper name pattern: the [Name] Ocean

Lina's grandmother sailed across the Atlantic Ocean from Lisbon to New York in 1962.

across the [Name] Ocean

Common collocations
  • Pacific Ocean
  • Atlantic Ocean
  • Indian Ocean
  • Arctic Ocean
  • Southern Ocean
  • the world's oceans
Synonyms
  • sea

    smaller named bodies (the Mediterranean Sea); not interchangeable with the named oceans

Grammar Patterns

the [Name] Ocean

Usage Note

Distinguish from sense 1: this sense is countable and always paired with a capitalised name (the Pacific Ocean, two oceans). Sense 1 is the general mass of water and almost never plural.

Common Mistakes

We flew over Pacific Ocean last night.
We flew over the Pacific Ocean last night.
proper-name oceans still need 'the'.
The earth has five ocean.
The earth has five oceans.
countable in this sense, so add the plural -s.
Idioms

a drop in the ocean

idiom

an amount so small compared with what is needed that it makes almost no real difference.

The donation of a thousand dollars is just a drop in the ocean for a hospital this size.

Recycling one bottle feels like a drop in the ocean, but millions of people doing it adds up.

an ocean of something

idiom

a very large amount or supply of something, usually more than anyone could need or count.

After the wedding, Aunt Rosa was left with an ocean of leftover food.

The new graduates faced an ocean of opportunities in the tech industry.

oceans of something

idiom

an informal way of saying there is a huge supply or quantity of something.

Don't worry about the deadline — we still have oceans of time before Friday.

The festival had oceans of free coffee for the volunteers.

Word family

  • oceanic
    adjectiveC1
  • oceanography
    nounC1
  • oceanographer
    nounC2
  • transoceanic
    adjectiveC2

Synonym discussion

Sense: noun/1

All three refer to the wide expanse of salty water, but they differ in register and scope. 'Ocean' is the most factual word and dominates American English; it suggests size, depth, and the planetary scale of the water — talk of pollution, climate, or long voyages usually picks 'ocean'. 'Sea' is the everyday British equivalent and is also used for smaller named bodies (the North Sea, the Mediterranean), so it feels closer and more local: 'a day at the sea' sounds like a beach trip, while 'a day at the ocean' sounds North American. 'The deep' is literary and dramatic, often hinting at danger or mystery, as in 'sailors lost to the deep'. Compare: 'The kids played by the sea' (cosy), 'The ship crossed the ocean' (epic), 'monsters from the deep' (poetic).

ocean ↗sea ↗the deep ↗

Common collocations

Nouns

  • ocean floor
  • ocean current
  • ocean wave
  • ocean view
  • ocean liner
  • ocean breeze

Phrases

  • the open ocean
  • the deep ocean
  • the world's oceans
  • swim in the ocean
  • cross the ocean

Prepositions

  • in the ocean
  • on the ocean
  • across the ocean
  • under the ocean
  • over the ocean

Etymology

GreekLatinOld FrenchMiddle EnglishEnglish

English borrowed 'ocean' in the 1300s from Old French 'occean', which came from Latin 'oceanus', itself from Greek 'Okeanos'. In Greek myth, Okeanos was the great river-god believed to circle the entire flat earth — so the word originally named one mythical encircling stream, not many separate seas. Once Europeans realised the world was round and mapped genuinely distinct waters, the same word was reused as a label for each of them: the Atlantic, Pacific, and so on. The everyday meaning of any large body of saltwater grew naturally out of that map-making sense.