sea

noun \ ˈsē \

Updated on: 10 Apr 2018

Definition of sea

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 : ²mare

—

sea

adjective

— at sea

1 : on the sea; specifically : on a sea voyage

2 : lost, bewildered

— to sea

: to or on the open waters of the sea

See sea defined for English-language learners

See sea defined for kids

Examples of sea in a Sentence

the seas of the Southern Hemisphere
millions of plants and animals live in the sea

Recent Examples of sea from the Web

For centuries, Viking seafarers ruled the North Atlantic, braving open seas peppered with icebergs to travel thousands of kilometers to their colonies in Iceland and Greenland—all without compasses.

— katie langin, Science | AAAS, "Top stories: black hole swarms, scientific misconduct, and recognizing mutt breeds," 6 Apr. 2018
Much like waves can cause rough seas, these waves can lead to bumpy flights for passengers on commercial airliners, particularly during takeoff and landing.

— matthew cappucci, Washington Post, "Wicked cool wave clouds crash over Boston area," 6 Apr. 2018
In many areas where beaches are privately owned, tourists and even local residents frequently wander over and set up their chairs, collect sea shells and build sand castles.

— craig pittman, miamiherald, "Does new law restrict public access to Florida’s beaches? Not exactly. | Miami Herald," 6 Apr. 2018
Indeed, a 2016 report from the National Oceanic and Atmospheric Administration found the average sea surface temperature globally rose about 1.5 degrees between 1901 and 2015.

— paul takahashi, Houston Chronicle, "Seafood restaurants squeezed by climate change, growing appetites," 6 Apr. 2018
In fact, whales were thought to live in an underwater society paralleling that above the sea.

— krista langlois, Smithsonian, "Why Scientists Are Starting to Care About Cultures Who Talk to Whales," 6 Apr. 2018
Even hyperbaric oxygen chambers have gone beyond the traditional use of saving the lives of deep-sea divers who surface too quickly.

— ronald d. white, latimes.com, "In L.A. today, fitness can mean IV drips, vitamin shots and a daily freeze at -292 degrees," 5 Apr. 2018
On Wednesday, President Rodrigo Duterte railed against unlicensed developments on the island and highlighted the outflow of raw sewage to the sea around it.

— david meyer, Fortune, "Zuckerberg Speaks, Oracle and Trump, YouTube Security: CEO Daily for April 5, 2018," 5 Apr. 2018
Ramses Ramirez from the Tokyo Institute of Technology and Amit Levi from the Harvard-Smithsonian Center for Astrophysics, for example, argue that the greenhouse gas can shift back and forth between deep-sea ice and the atmosphere.

— shannon hall, Scientific American, "Are Water Worlds Habitable?," 5 Apr. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'sea.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of sea

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

NEW! Time Traveler

First Known Use: before 12th century

See Words from the same year

sea Synonyms

Synonyms

blue, brine, deep, ocean, seven seas;

Related Words

blue water, high seas, main, waters;

basin;

Davy Jones's locker, depths;

Other Oceanography Terms

littoral, sound

SEA Defined for English Language Learners

sea

noun

Definition of sea for English Language Learners

: the salt water that covers much of the Earth's surface ( literary )
: a large body of water that is part of the sea or that has land around part or all of it
: an area of the sea