Spendthrift is a noun that refers to a person who spends money wastefully.
Our word of the day combines the words ‘spend’ and ‘thrift’ to mean someone who spends their money in an irresponsible, reckless way.
I wouldn’t have given my nephew so much money for his birthday if I’d known what a spendthrift he was. After he got done buying news shoes and a new suit, and new laptop, he had nothing left to pay his rent with.