Definition of

Sub

  1. (noun, artifact) a submersible warship usually armed with torpedoes
  2. (noun, food) 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
  3. (verb, possession) be a substitute
    The skim milk substitutes for cream--we are on a strict diet

via WordNet, Princeton University

Note: If you're looking to improve your vocabulary right now, we highly recommend Ultimate Vocabulary Software.

Word of the Moment

Hubby

a married man; a woman's partner in marriage