The Collaborative International Dictionary of English v.0.48:

Spendthrift \Spend"thrift`\, n.
   One who spends money profusely or improvidently; a prodigal;
   one who lavishes or wastes his estate. Also used
   figuratively.
   [1913 Webster]

         A woman who was a generous spendthrift of life. --Mrs.
                                                  R. H. Davis.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Spendthrift \Spend"thrift\, a.
   Prodigal; extravagant; wasteful.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

26 Moby Thesaurus words for "spendthrift":
   big-time spender, dissipative, easy come, easy go, extravagant,
   improvident, incontinent, intemperate, lavish, overgenerous,
   overlavish, overliberal, penny-wise and pound-foolish,
   pound-foolish, prodigal, prodigal son, profligate, profuse,
   spend-all, spender, squanderer, squandering, wasteful, waster,
   wastethrift, wastrel