disapproval If you call someone a spendthrift, you mean that they spend too much money. Spendthrift is also an adjective. his father's spendthrift ways. someone who spends money carelessly, even when they do not have a lot of it (spend + thrift (14-19 centuries))
One who spends money profusely or improvidently; a prodigal; one who lavishes or wastes his estate
{i} one who wastes money, big spender, one who disburses money or possessions extravagantly
A trust that is created for the benefit of a person (often because that beneficiary is unable to control spending) that gives an independent trustee full authority to make decisions as to how the trust funds may be spent for the benefit of the beneficiary, thus keeping the funds in the trust beyond the reach of creditors