submarinˈer (or /-marˈin-/) noun

A member of the crew of a submarine

submarine canyon noun (geology)

A trench on the continental shelf, sometimes with tributaries

submarine effect noun

One in which the occupant of a vehicle simultaneously moves forward and slides out from under the seat belt, esp during a collision, rendering him or her vulnerable to an increased risk of injury

submarine sandwich noun

A large sandwich made with a bread roll long, thin and rounded enough to suggest the shape of a submarine