The Collaborative International Dictionary of English v.0.48:

bomber \bomber\ n.
   1. a military aircraft that drops bombs during flight.
      [WordNet 1.5]

   2. a large sandwich on a long crusty roll that is 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 US.

   Syn: grinder, hero, hero sandwich, hoagie, hoagy, Cuban
        sandwich, Italian sandwich, poor boy, sub, submarine,
        submarine sandwich, torpedo, wedge, zep.
        [WordNet 1.5]

   3. a person who drops bombs or plants and explodes bombs,
      especially surreptitously.
      [PJC]

   4. a bomber jacket.
      [PJC]

WordNet (r) 3.0 (2006):

bomber
    n 1: a military aircraft that drops bombs during flight
    2: a person who plants bombs
    3: 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]