noun
plural seas
the salt water that covers much of the Earth's surface [noncount]
b or Sea [count] :a large body of water that is part of the sea or that has land around part or all of it
see color picture - see also seven seas
[count] :an area of the sea - used to describe the movement of the water in the sea
[count] :a large amount or number of people or things spread over a large area - usually singular
or Sea [count] technical :one of the large, flat areas on the moon or on Mars
at sea
sailing or traveling on the sea
confused and not confident
between the devil and the deep blue sea
fish in the sea
go to sea
somewhat old-fashioned :to become a sailor
out to sea
toward or into a part of the ocean that is far away from land
put (out) to sea
to leave a port, harbor, etc., and begin traveling on the sea