WordNet (r) 3.0 (2006):

zep
    n 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 [syn: bomber,
         grinder, hero, hero sandwich, hoagie, hoagy,
         Cuban sandwich, Italian sandwich, poor boy, sub,
         submarine, submarine sandwich, torpedo, wedge,
         zep]