The Collaborative International Dictionary of English v.0.48:

Squanderer \Squan"der*er\ (-[~e]r), n.
   One who squanders.
   [1913 Webster]

WordNet (r) 3.0 (2006):

squanderer
    n 1: a recklessly extravagant consumer [syn: prodigal,
         profligate, squanderer]