4
whacky
4
wrong(adjective, foolish, unreasonable, sane, illogical)
4
zealot(noun, person, crazy, nut, fanatic)
3
bugs
3
cockamamie(adjective, weak, simple, wrong, silly)
3
dim-witted(adjective, foolish)
3
doltish(adjective, weak, simple, careless, silly)
3
fatuitous
3
flake(noun, slang, sick, mad person)
3
ignorant(adjective, foolish, impractical, half-baked, doomed)
3
infatuated
3
madcap(noun, adjective, person, silly, crazy)
3
moron(noun, person)
3
odd(adjective, wild, strange, silly, foolish)
3
oddball
3
off(adjective, sane)
3
off one's rocker(adjective, idiom, sane)
3
queer
3
rabid(adjective, crazy, mad, odd, insane)
3
rash(adjective, crazy, mad, odd, insane)
11 years ago|25k views|share |citing 
APASmart Define. (2015). loony thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/loony/thesaurus/synonyms
ChicagoSmart Define. 2015. "loony thesaurus" https://smartdefine.org/loony/thesaurus/synonyms (accessed September 24, 2026).
HarvardSmart Define 2015, loony thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/loony/thesaurus/synonyms>.
MLASmart Define. "loony thesaurus" 10 April 2015. Web. 24 September 2026. <https://smartdefine.org/loony/thesaurus/synonyms>