sea

American  

[see] / si /

noun

• seas
  plural

1. the salt waters that cover the greater part of the earth's surface.

2. a division of these waters, of considerable extent, more or less definitely marked off by land boundaries.

   the North Sea.

3. one of the seven seas; ocean.

4. a large lake or landlocked body of water.

5. the degree or amount of turbulence of the ocean or other body of water, as caused by the wind.

6. the waves.

7. a large wave.

   The heavy seas almost drowned us.

8. a widely extended, copious, or overwhelming quantity.

   a sea of faces; a sea of troubles.

   Synonyms:

   mass, abundance, host, multitude

9. the work, travel, and shipboard life of a sailor.

   The sea is a hard life but a rewarding one.

10. Astronomy. mare.

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adjective

1. of, relating to, or adapted for use at sea.

idioms

1. at sea, Also

   1. on the ocean.

   2. perplexed; uncertain.

      completely at sea as to how to answer the question.

2. go to sea,

   1. to set out on a voyage.

   2. to embark on a nautical career.

3. half seas over, partly or completely drunk: Also

   They came home at dawn, looking half seas over.

4. put to sea, to embark on a sea voyage: Also put out to sea.

   The expedition is nearly ready to put to sea.

5. follow the sea, to pursue a nautical career.

   Many boys then dreamed of following the sea.

sea British  

/ siː /

noun

1. 1. the mass of salt water on the earth's surface as differentiated from the land

   2. ( as modifier )

      sea air

2. (capital when part of place name)

   1. one of the smaller areas of ocean

      the Irish Sea

   2. a large inland area of water

      the Caspian Sea

3. turbulence or swell, esp of considerable size

   heavy seas

4. (capital when part of a name) astronomy any of many huge dry plains on the surface of the moon See also mare 2

5. anything resembling the sea in size or apparent limitlessness

6. the life or career of a sailor (esp in the phrase follow the sea )

7. 1. on the ocean

   2. in a state of confusion

8. to become a sailor

9. to embark on a sea voyage

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sea Scientific  

/ sē /

1. The continuous body of salt water that covers most of the Earth's surface.

2. A region of water within an ocean and partly enclosed by land, such as the North Sea.

3. See Note at ocean

4. A large body of either fresh or salt water that is completely enclosed by land, such as the Caspian Sea.

5. Astronomy A mare.

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sea More Idioms  

More idioms and phrases containing sea

• at sea
• between a rock and a hard place (devil and the deep blue sea)
• high seas
• not the only fish in the sea
• put out (to sea)

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Other Word Forms

Noun Inflected Forms

• seas
  plural

Etymology

Origin of sea

First recorded before 900; Middle English see, Old English sǣ; cognate with Dutch zee, German See, Old Norse sær “sea,” Gothic saiws “marsh”

Explanation

A sea is a huge body of salt water, typically a part of the ocean that's near land. Much grander than a lake or river, a sea can appear open and endless when you view it from the shore. The best-known examples of sea include the Mediterranean Sea, Bering Sea, and Caribbean Sea. The word sea can also refer to large waves. If there's a sea warning, it would be wise to reschedule your sailing trip. Sea can be used more figuratively to describe something that seems to be vast in quantity, just like the sea. The audience at your concert might look like an endless sea of people.

Example Sentences

See Examples For:

sea seas

The second course featured sesame-crusted sea bass with baby bok choy and roasted garden eggplant.

From The Wall Street Journal ● Sep. 25, 2026

The figures include a dinghy carrying 51 people which departed from Normandy, much further west than small boats typically set off, on Monday morning and spent more than 33 hours at sea.

From BBC ● Sep. 24, 2026

The shockwave created by a jet breaking the sound barrier restricted Concorde to flights over the sea and barred it from lucrative routes across the US.

From BBC ● Sep. 24, 2026

Together, those changes extended the annual melt season and contributed to major losses of sea ice across the Arctic.

From Science Daily ● Sep. 23, 2026

My father came out of the shed huddled up in his parka and turned away from the sea, blinking in the wan light, smiling a wan smile.

From "Black Star, Bright Dawn" by Scott O'Dell

But forecasters said they could stir up rough seas and send swells toward the California coast, which already has been battered by big waves this summer.

From Los Angeles Times ● Sep. 24, 2026

Russia has ports on the Baltic and Caspian seas, and has sought to support farmers by offering subsidies for rail transport of grain.

From The Wall Street Journal ● Sep. 24, 2026

But as afternoon winds whipped up and the seas grew rough, the boat took on water as they returned to shore and began to sink about 600 yards off Alcatraz Island.

From Los Angeles Times ● Sep. 18, 2026

Iestyn Morgan said he wants to raise awareness about the 'threats our seas are facing'

From BBC ● Sep. 14, 2026

They continued bearing eastward, still shipping seas over their bows, still wet and cold.

From "Shipwreck at the Bottom of the World" by Jennifer Armstrong

Related Words

• expanse
• lake
• ocean
• pond
• surf