IPA: /ˈfuːlɪʃli/
KK: /ˈfuːlɪʃli/
In a way that shows a lack of good sense or judgment.
He foolishly spent all his savings on a new car.
Foolishly → It is formed from "fool" (from Old English *fola*, meaning a person lacking in judgment) and the suffix "-ishly" (meaning in a manner of). The word "foolishly" means in a manner that lacks judgment or wisdom.
Think of someone acting like a 'fool' — that's why 'foolishly' means behaving in a way that lacks good judgment.