a submersible warship usually armed with torpedoes
a large sandwich made of a long crusty roll split lengthwise and filled with meats and cheese (and tomato and onion and lettuce and condiments); different names are used in different sections of the United States
Adjective:
beneath the surface of the sea
Verb:
move forward or under in a sliding motion;
"The child was injured when he submarined under the safety belt of the car"