noun

• A large body of salt water.
• The ocean; the continuous body of salt water covering a majority of the Earth's surface.
• A body of salt water smaller than an ocean, generally forming part of, or connecting with, an ocean or a larger sea.
• A lake, especially if large or if salty or brackish.
• The swell of the sea; a single wave; billow.
• (attributive, in combination) Living or used in or on the sea; of, near, or like the sea.
• (figurative) Anything resembling the vastness or turbulence of the sea.
• (physics) A constant flux of gluons splitting into quarks, which annihilate to produce further gluons.
• (planetology) A large, dark plain of rock; a mare.
• (planetology) A very large lake of liquid hydrocarbon.
• A surname.
• A hamlet in Ilminster parish, South Somerset district, Somerset, England (OS grid ref ST3413).
• (sports) Abbreviation of Seattle. [A seaport and the largest city in Washington, United States, and the county seat of King County.]
• Initialism of Southeast Asia. [A subregion of Asia, comprising the territories of Brunei, Cambodia, East Timor, Indonesia, Laos, Malaysia, Myanmar (Burma), the Philippines, Singapore, Thailand, and Vietnam.]
• Initialism of Single European Act.
• Initialism of Strategic Environmental Assessment.