sub

noun

1.
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
bomber Cuban sandwich grinder hero hero sandwich hoagie hoagy Italian sandwich poor boy submarine submarine sandwich torpedo wedge zep
2.
a submersible warship usually armed with torpedoes
pigboat submarine