IPA: //mɪsˈspɛnd//
KK: /mɪsˈspɛnd/
To use money or resources in a way that is not wise or effective, often wasting them instead of using them for a good purpose.
He regretted how he misspent his savings on unnecessary things.
Past: misspent
Past Participle: misspent
Misspend → It is formed from "mis-" (meaning wrongly or badly) and "spend" (from Old English "spendan", meaning to expend or use). The word "misspend" means to use or expend resources in a wrong or unwise manner.
Think of using resources 'wrongly' ('mis-') — that's why misspend means to spend in a bad way.