Unthriftily is an adjective that refers to the act of spending money recklessly or carelessly. When referring to unthriftily, words like wastefully, improvidently, and prodigally can be used interchangeably. Another word that shares a similar meaning to unthriftily is extravagantly, which describes actions that are excessive or going beyond the expected limit. Other synonyms for unthriftily include spendthrift, careless, and thoughtless. Each of these words highlights the negative impact and consequences of being unthriftily, particularly in terms of finances. It is important to learn how to budget wisely and avoid unthriftily behavior.