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

On a Friday night, driving there from Venice would be insane. — Solange Neustadter, Los Angeles Times, 10 July 2026

Tangible mailers, high-end lookbooks or tactile packaging inserts humanize the brand, drive insane recall and make the digital experience unforgettable. — Expert Panel®, Forbes.com, 10 July 2026

England’s 2-1 victory against Mexico — and that insane Azteca Stadium crowd — also was richly deserved. — Miami Herald, 7 July 2026

Erling Haaland came very close with his brace against Brazil but Bellingham’s goals and graft under insane pressure in the Azteca was the international performance of his life to date. — Stuart James, New York Times, 7 July 2026