spendthrift

A spendthrift person is reckless and wasteful with his money. If you're a spendthrift, you might find yourself in debt. However, it might be fun to have a spendthrift friend who likes to treat you to expensive lunches and lavish gifts.

Spendthrift was created by sticking two opposite words together: spend and thrift, which means “savings, wealth.” So a spendthrift spends all of his savings. Spendthrift people are the worst nightmare of retirement planners and Scrooges all over the globe. So unless you want to be called a spendthrift, think twice about your next purchase.

Definitions of spendthrift
1

n someone who spends money prodigally

Synonyms:
scattergood, spend-all, spender
Types:
big spender, high roller
one who spends lavishly and ostentatiously on entertainment
Type of:
prodigal, profligate, squanderer
a recklessly extravagant consumer

adj recklessly wasteful

Synonyms:
extravagant, prodigal, profligate
wasteful
tending to squander and waste