Foolish.
To act with folly; act foolishly.
noun.
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.
noun.
Something regard for or attention to which is foolish.
noun.
Specifically Conduct morally bad; wickedness; wantonness.
noun.
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.
noun.
Synonyms Nonsense, foolishness, senselessness, ridiculousness, extravagance, indiscretion, imbecility. See list under absurdity.