Synonyms of insane

insane

adjective

(ˌ)in-ˈsān 

1

as in mad

unable to think in a clear or sensible way

After learning of the robbery, they were insane with anger and foolishly searched the neighborhood looking for their belongings.

Synonyms & Similar Words

• mad
• maniacal
• crazy
• mental
• nuts
• crazed
• psycho
• psychotic
• demented
• disturbed
• deranged
• unhinged
• unbalanced
• foolish
• strange
• irrational
• loco
• nutty
• bonkers
• around the bend
• certifiable
• off
• batty
• daft
• eccentric
• depressed
• cracked
• out to lunch
• haywire
• obsessed
• unsound
• non compos mentis
• brainsick
• unreasonable
• queer
• ballistic
• fey
• distracted
• distraught
• frantic
• delusional
• delirious
• bats
• hysterical
• loopy
• crackers
• odd
• off one's rocker
• off one's gourd
• wud
• delusionary
• off one's head
• disordered
• nuclear
• out of one's head
• oddball
• aberrant
• dotty
• berserk
• touched
• witless
• pixilated
• senseless
• frenzied
• monomaniacal
• raving
• potty
• teched
• ape
• monomaniac
• fixated
• amok
• wigged-out
• bananas

Antonyms & Near Antonyms

• sane
• reasonable
• sound
• balanced
• rational
• clear
• normal
• wise
• sensible
• lucid
• uncrazy
• judicious
• compos mentis
• healthy
• well-adjusted
• unneurotic

2

as in absurd

conceived or made without regard for reason or reality

a completely insane plan to build an opera house in the middle of nowhere

Synonyms & Similar Words

• absurd
• bizarre
• foolish
• unreal
• crazy
• fantastic
• strange
• ridiculous
• wild
• fanciful
• nonsensical
• incredible
• preposterous
• curious
• grotesque
• weird
• off the wall
• peculiar
• unbelievable
• odd
• funny
• inconceivable
• unthinkable
• unimaginable
• eccentric
• implausible
• extravagant
• ludicrous
• wacky
• outlandish
• surreal
• quirky
• laughable
• queer
• kinky
• nightmarish
• screwy
• quaint
• farcical
• out-of-the-way
• outré
• kooky
• Alice-in-Wonderland
• dreamlike
• way-out
• bizarro
• far-out
• queerish
• Kafkaesque

Antonyms & Near Antonyms

• reasonable
• realistic

3

as in stupid

showing or marked by a lack of good sense or judgment

an insane plan to blow all of their savings on lottery tickets

Synonyms & Similar Words

• stupid
• crazy
• absurd
• silly
• foolish
• mad
• idiotic
• irrational
• lunatic
• ridiculous
• unreasonable
• fool
• loony
• dumb
• nonsensical
• wacky
• zany
• simple
• asinine
• nutty
• preposterous
• kooky
• unwise
• wacko
• fatuous
• daft
• weak
• unreasoning
• cuckoo
• senseless
• daffy
• inept
• batty
• witless
• out to lunch
• slow
• barmy
• jerky
• gaga
• crackpot
• weak-minded
• simpleminded
• brainless
• harebrained
• dippy
• screwball
• dotty
• crackbrained
• loony tunes
• sappy
• balmy
• moronic
• cockeyed
• meshuga
• illogical
• half-baked
• unreasoned
• lunkheaded
• tomfool
• imbecile
• bubbleheaded
• ludicrous
• half-witted
• featherheaded
• thoughtless
• clueless
• feebleminded
• fruity
• dull
• unintelligent
• dense
• obtuse
• mindless
• brain-dead
• dopey
• laughable
• vacuous
• opaque
• invalid
• doltish
• lamebrain
• dim
• thickheaded
• fallacious
• farcical
• dorky
• dunderheaded
• pinheaded
• oafish
• unsound
• nonrational
• empty-headed
• thick
• softheaded
• surd
• gormless
• soft
• knuckleheaded
• clownish
• dim-witted
• chuckleheaded
• airheaded
• notional
• ill-advised
• buffoonish
• slow-witted
• boobish
• chowderheaded
• birdbrained
• unconsidered

Antonyms & Near Antonyms

• wise
• sane
• sound
• sensible
• prudent
• reasonable
• judicious
• intelligent
• clever
• smart
• bright
• logical
• valid
• rational
• sagacious
• sage
• sapient
• brainy
• well-advised

4

as in excessive

going beyond a normal or acceptable limit in degree or amount

wanted an insane amount of money to paint our house

Synonyms & Similar Words

• excessive
• extreme
• steep
• extravagant
• endless
• infinite
• lavish
• exorbitant
• over-the-top
• intolerable
• inordinate
• unconscionable
• unbearable
• undue
• fancy
• baroque
• immoderate
• inappropriate
• devilish
• unmerciful
• plethoric
• overdue
• overextravagant
• stiff
• towering
• overweening
• improper
• limitless
• unjustifiable
• boundless
• a bit much
• immeasurable
• overmuch
• unwarranted
• unseemly
• unrestrained
• thick

Antonyms & Near Antonyms

• reasonable
• moderate
• modest
• inadequate
• insufficient
• deficient
• minimum
• minimal
• temperate
• middling

Example Sentences

Recent Examples of insane

Plus, 2025 was a huge touring year for me, and getting this done was insane. — Daniel Kohn, Rolling Stone, 15 Oct. 2026

That may be the name of her next album, but Venus’ insane popularity also speaks to the way Metropia is moving forward, constantly looking for the next shiny thing. — Kate Erbland, IndieWire, 10 Oct. 2026

Derek wants to hear Julia audibly breathing next week, which is both a hilarious and insane request. — Maggie Fremont, Vulture, 7 Oct. 2026

Those questions triggered some insane accusations from Aces fans regarding the Fever fan and their fanbase. — Jon Root Outkick, FOXNews.com, 2 Oct. 2026