I. “+ noun
Etymology: Middle English, from un- (I) + thrift
1. : lack of thrift : extravagance , wastefulness
the repression of unthrift and dissipation — James Ford
2. : an extravagant person : spendthrift , wastrel
like unthrifts, having spent your stock, and needy grown — John Drinkwater
II. “+ adjective
: extravagant , lavish , unthrifty
in an unthrift generosity, has given it with a much more valuable present — J.G.Lockhart