[sea] n [ME see, fr. OE sae; akin to OHG se sea, Goth saiws] (bef. 12c) 1 a: a great body of salty 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 ~" c: ocean d: an inland body of water--used esp. for names of such bodies "the Caspian Sea" "the Sea of Galilee"
2. a: surface motion on a large body of water or its direction; also: a large swell or wave--often used in pl. "heavy ~s" b: the disturbance of the ocean or other body of water due to the wind
3: something likened to the sea esp. in vastness "the crowd was a ~ of faces"
4: the seafaring life
5: [3]mare -- sea adj -- at sea 1: on the sea; specif: on a sea voyage
2: lost, bewildered -- to sea : to or on the open waters of the sea