The Collaborative International Dictionary of English v.0.48:

Weaponry \Weap"on*ry\, n.
   Weapons, collectively; as, an array of weaponry. [Poetic]
   [1913 Webster]

WordNet (r) 3.0 (2006):

weaponry
    n 1: weapons considered collectively [syn: weaponry, arms,
         implements of war, weapons system, munition]