The Collaborative International Dictionary of English v.0.48:

Spender \Spen"der\, n.
   One who spends; esp., one who spends lavishly; a prodigal; a
   spendthrift.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Spender
    n 1: English poet and critic (1909-1995) [syn: Spender,
         Stephen Spender, Sir Stephen Harold Spender]
    2: someone who spends money prodigally [syn: spendthrift,
       spend-all, spender, scattergood]
    3: someone who spends money to purchase goods or services [syn:
       spender, disburser, expender]