Meaning of SEA in English
1》 the expanse of salt water that covers most of the earth's surface and surrounds its land masses.
↘a roughly definable area of this: the Black Sea.
↘(also ~s ) waves as opposed to calm ~.
2》 a vast expanse or quantity: a ~ of faces.
1》 sailing on the ~.
2》 (also all at ~ ) confused; uncertain.
put ( out ) to ~ leave land on a voyage.
one's ~ legs one's ability to keep one's balance and not feel ~sick on board a moving ship.
~ward adjective & adverb
OE s , of Gmc origin.
Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004