(~s)
1.
A ~ is a type of ship that can travel both above and below the surface of the sea. The abbreviation sub is also used.
...a nuclear ~.
N-COUNT
2.
Submarine means existing below the surface of the sea. (FORMAL)
...~ caves.
...~ plants.
ADJ: ADJ n
3.
A ~ sandwich is a long soft bread roll filled with a combination of things such as meat, cheese, eggs, and salad. The abbreviation sub is also used. (AM)
N-COUNT: usu N n