sea

noun

ˈsē 

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

: mare entry 2

sea adjective

see also at sea, to sea

Synonyms of sea

• ocean
• waters

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

On Saturday night and early Sunday, forecasters expect wind and snow that could lead to blizzard conditions before the storm starts to move to sea. —Arkansas Online, 31 Jan. 2026

The moon and Jupiter will be close enough to fit comfortably in the field of view of a pair of 10X50 binoculars, which will help reveal the dark lunar seas and prominent craters scarring the surface of Earth's natural satellite. —Anthony Wood, Space.com, 30 Jan. 2026

The region has lost sea-ice habitat more than twice as fast as any other area where polar bears live. —Amarachi Orie, CNN Money, 30 Jan. 2026

Polar bears in Svalbard are getting fatter, even as sea ice disappears. —semafor.com, 30 Jan. 2026

Word History

Etymology

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

First Known Use

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

Phrases Containing sea

• beam sea
• between the devil and the deep blue sea
• by sea
• California sea lion
• Chilean sea bass
• deep-sea
• fish in the sea
• go to sea
• high sea
• many/plenty more fish in the sea
• not the only fish in the sea
• out to sea
• put (out) to sea
• sea air
• sea anchor
• sea anemone
• sea bass
• sea bed
• sea biscuit
• sea bream
• sea breeze
• sea captain
• sea change
• sea chest
• sea cow
• sea crayfish
• sea cucumber
• sea devil
• sea dog
• sea duck
• sea duty
• sea eagle
• sea fan
• sea fire
• sea floor
• sea grape
• sea green
• sea hare
• sea holly
• sea island cotton
• sea kale
• sea king
• sea lamprey
• sea-lane
• sea lavender
• sea lawyer
• sea legs
• sea lettuce
• sea level
• sea lily
• sea lion
• sea-maid
• sea-maiden
• sea mew
• sea mile
• sea monkey
• sea monster
• sea mouse
• sea nettle
• sea oats
• sea onion
• sea otter
• sea pen
• sea pink
• sea power
• sea puss
• sea robin
• sea room
• sea rover
• sea-run
• sea salt
• sea scallop
• sea scorpion
• sea serpent
• sea slug
• sea snake
• sea spider
• sea squirt
• sea star
• sea stores
• sea trout
• sea turtle
• sea urchin
• sea wasp
• sea whip
• sea wrack
• spotted sea trout
• Steller's sea cow
• sub-sea
• swept out to sea
• the open sea
• wash out to sea
• white sea bass

Rhymes for sea

• be
• bee
• bree
• cree
• fee
• flea
• flee
• free
• gee
• ghee
• glee
• he

Kids Definition

sea

noun

ˈsē 

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

c

: ocean sense 1

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

: mare entry 2

sea adjective