Spendthrift

1. (n.) One who spends money profusely or improvidently; a prodigal; one who lavishes or wastes his estate. Also used figuratively.

2. (a.) Prodigal; extravagant; wasteful.

Thesaurus Entries

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