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

Prosecutor Sarah George, the Chittenden County state’s attorney, argued that Eaton was not legally insane and understood that his actions were criminal. — Christina Coulter, PEOPLE, 22 Sep. 2026

It’s being sold all over the world; it’s being taught in colleges, which is insane to me. — Alex Gonzalez, VIBE.com, 18 Sep. 2026

Sure, this sounds insane, but the real insanity is how much New York mismanages its education system and how little attention the problem receives in Albany. — Zilvinas "z" Silenas, New York Daily News, 14 Sep. 2026

Traditionally, the solution – aside from squaddies hauling insane loads on their backs – has been to use horses and mules to do the job. — New Atlas, 13 Sep. 2026