1
a
: a great body of salt water that covers much of the earth
broadly : the waters of the earth as distinguished from the land and air
b
: a body of salt water of second rank more or less landlocked
the Mediterranean sea
c
: ocean
d
: an inland body of water
used especially for names of such bodies
the Caspian Sea
2
a
: surface motion on a large body of water or its direction
also : a large swell or wave
often used in plural
heavy seas
b
: the disturbance of the ocean or other body of water due to the wind
3
: something likened to the sea especially in vastness
a sea of faces
4
: the seafaring life
5
sea adjective
Phrases
at sea
1
: on the sea
specifically : on a sea voyage
2
to sea
: to or on the open waters of the sea

Examples of sea in a Sentence

the seas of the Southern Hemisphere millions of plants and animals live in the sea
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The successful trial marks the first time a naval variant of the IRIS-T family missile has been launched at sea, paving the way for serial introduction across the fleet. Aamir Khollam, Interesting Engineering, 17 Oct. 2025 Some stars collapsed to the sea floor, dissolved into piles of goo. JSTOR Daily, 17 Oct. 2025 Some firms have scurried to ship early, but even a few days’ delay at sea could blow up their margins. Veronique De Rugy, Oc Register, 17 Oct. 2025 Every night after dusk, one of the world’s largest migrations begins, as deep sea creatures rise to the surface to feed. New York Times, 16 Oct. 2025 See All Example Sentences for sea

Word History

Etymology

Middle English see, from Old English ; akin to Old High German sea, Goth saiws

First Known Use

before the 12th century, in the meaning defined at sense 1a

Time Traveler
The first known use of sea was before the 12th century

Browse Nearby Words

Cite this Entry

“Sea.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/sea. Accessed 17 Oct. 2025.

Kids Definition

sea

noun
1
a
: a great body of salty water that covers much of the earth
also : the waters of the earth
b
: a body of salt water not as large as an ocean
the Mediterranean Sea
d
: an inland body of water either salt or fresh
the Sea of Galilee
2
: rough water
a high sea swept the deck
3
: something suggesting the sea (as in great size or depth)
a golden sea of wheat
4
: a life involving marine travel
hoped to make a career of the sea
5
sea adjective

More from Merriam-Webster on sea

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