Synonyms of foolishness

1 Syllable
bs, hooey, crap, guff, bunk
2 Syllables
crapping, follies, weakness, daftness, folly, hogwash, madness, piffle, dumbness, twaddle, claptrap, rubbish, slip-up, foul-up, misspeak, screw-up
3 Syllables
poppycock, mistake, goofiness, idiocies, idiocy, dottiness, witlessness, fatuity, crudeness, flapdoodle, lunacies, craziness, levities, drolleries, mindlessness, drollery, dopiness, absurdness, carrying-on, levity, tommyrot, nonsense, lunacy, cretinism, silliness, foolery, malarkey, tactlessness
4 Syllables
insanity, absurdities, inaneness, absurdity, stupidity, imprudence, tomfoolery, indiscretions, inanity, senselessness, ludicrousness, facetiousness, rigmarole, hokey-pokey, mischief-making, unwiseness, indiscretion, ingenuousness
5 Syllables
preposterousness, asininity, simplemindedness, simple-mindedness
6 Syllables
illogicality, unreasonableness, impracticality, irrationality, irrationalities, insensibility, excitability, illogicalities
7 Syllables
inadvisability, irresponsibility