spendthrift
someone who spends money prodigiously and who is extravagant and recklessly wasteful, often to a point where the spending climbs well beyond her or his means
en-GB/ˈspɛndθɹɪft/
en-US/ˈspɛndˌθɹɪft/
someone who spends money prodigiously and who is extravagant and recklessly wasteful, often to a point where the spending climbs well beyond her or his means