What does sea mean?
The sea is a large body of salt water, usually larger than a lake and smaller than an ocean. It may refer broadly to the waters surrounding the continents or to a particular geographic body such as the Baltic Sea. In everyday expressions, the word carries a strong association with the coast, sailing, fishing, weather, and the dangers of deep water. Phrases such as "at sea," "by sea," and "open sea" are common, while literary usage can present the sea as a symbol of vastness, uncertainty, freedom, or mystery. Although people normally speak of multiple seas, the singular form is also idiomatic when referring to the sea as a general environment. The word is also the source of many terms associated with ships and the maritime world, including marine, maritime, mariner, and submarine.
A large body of salt water or a particular expanse of water associated with a coastline.
"Small waves rolled across the sea beneath a cloudless sky."
The word is commonly used in both general and proper geographical senses. In figurative expressions, it can indicate uncertainty, difficulty, or a wide range of possibilities.
To put or sail a vessel out to sea.
"The captain seaed the boat while the passengers remained ashore."
This use is now uncommon and is mainly found in older, literary, or maritime language.
Use "seas" for multiple distinct bodies of water or for different areas of a large body of water.
"The northern seas are rougher than the sheltered waters closer to shore."
The word sea also became the root of maritime language: mariners, submarines, and marine biology all point back to the Latin word for the sea.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does sea come from?
The word descends from Old English sæ, meaning a large body of water. Its cognates include Old Norse sær and Old Saxon sai, all of which trace to the Proto-Germanic *saiwaz. The Latin word mare, a separate but relevant source for many maritime vocabulary items, gave rise to forms such as marine, maritime, and submarine.
Related word forms
How sea is actually used
In general use, "sea" often means a specific named or geographically defined body of water, while "ocean" usually refers to one of the world's largest interconnected oceans. The expression "at sea" can mean literally aboard a vessel or figuratively in a state of uncertainty.
Easily confused with sea
Sea is a large body of salt water, whereas see means to perceive with the eyes or to understand.