sub

Noun

• 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

Verb

• be a substitute
  • The young teacher had to substitute for the sick colleague
    
  • The skim milk substitutes for cream--we are on a strict diet
    

Related words

• Synonyms: 
  submarine , pigboat , U-boat , substitute , stand in , fill in