Synonyms of tomfoolery

1 Syllable
crap, jig, bunk, fun, prank
2 Syllables
hijinks, antic, humor, folly, frolic, capers, madness, crapping, clowning, caper, humors, take-in, antics, joking
3 Syllables
idiocy, roughhousing, merriment, rowdiness, nuttiness, wackiness, flakiness, foolishness, giddiness, craziness, carrying-on, tommyrot, prankishness, idiocies, horseplay, impishness, roguery, roguishness, lunacy, capering, cretinism, foolery, silliness, skylarking, mummery
4 Syllables
insanity, buffoonery, jocosity, shenanigan, senselessness, shenanigans, ludicrousness, horsefeathers, absurdity, mischievousness, rascality, unwiseness, espieglerie
5 Syllables
ridiculousness, imbecility
7 Syllables
irresponsibility