n. The character or conduct of a fool; the state of being foolish; weakness of judgment or character, or actions which spring from it; want of understanding; weak or light-minded conduct.n. Something regard for or attention to which is foolish.n. Specifically Conduct morally bad; wickedness; wantonness.n. A costly structure or other undertaking left unfinished for want of means, too expensive to be properly maintained, built in a very ill-chosen place, or the like; an enterprise that exhausts or ruins the projector.n. Synonyms Nonsense, foolishness, senselessness, ridiculousness, extravagance, indiscretion, imbecility. See list under absurdity.To act with folly; act foolishly.Foolish.