5
queer(adjective, crazy, cuckoo)
5
round the bend(expression, idiom, silly, foolish, mad)
5
scatterbrained
5
schizoid
5
sick(adjective, crazy, mad, ill, unhealthy)
5
tomfool(adjective, knowledge, ability, foolish)
5
unstable(false, foolish, mad, unreasonable, ill)
5
unthinking(adjective, foolish, unreasonable, illogical)
5
violent(adjective, wild, mad, vicious, fierce)
4
reckless(adjective, silly, thoughtless, unwise)
4
abnormal(adjective, fanatical, preoccupied, infatuated, neurotic)
4
bats
4
bughouse
4
disconnected(adjective, foolish, unreasonable, chaotic, illogical)
4
dull(foolish, crazy)
4
fantastic(adjective, weak, simple, strange, silly)
4
feverish
4
flaky(adjective, simple, silly, foolish, crazy)
4
hare-brained(adjective, silly, foolish, crazy, zany)
4
imbecile(foolish, crazy)
11 years ago|34k views|share |citing 
APASmart Define. (2015). insane thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/insane/thesaurus/synonyms
ChicagoSmart Define. 2015. "insane thesaurus" https://smartdefine.org/insane/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2015, insane thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/insane/thesaurus/synonyms>.
MLASmart Define. "insane thesaurus" 10 April 2015. Web. 23 September 2026. <https://smartdefine.org/insane/thesaurus/synonyms>