Synonyms of preposterous

preposterous

adjective

pri-ˈpä-st(ə-)rəs 

1

as in absurd

conceived or made without regard for reason or reality

the idea that extraterrestrials built the pyramids is preposterous

Synonyms & Similar Words

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

Antonyms & Near Antonyms

• reasonable
• realistic

2

as in silly

showing or marked by a lack of good sense or judgment

a preposterous suggestion to go swimming in this freezing weather

Synonyms & Similar Words

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

Antonyms & Near Antonyms

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

3

as in ridiculous

so foolish or pointless as to be worthy of scornful laughter

the movie thriller had such a preposterous plot that we were on the edge of our seats snickering

Synonyms & Similar Words

• ridiculous
• absurd
• silly
• pathetic
• foolish
• ludicrous
• comical
• stupid
• unreasonable
• laughable
• farcical
• irrational
• risible
• dumb
• incredible
• derisive
• insane
• derisory
• crazy
• cockamamy
• for the birds
• fantastic
• idiotic
• asinine
• inane
• nonsensical
• fatuous
• mad
• moronic
• inconceivable
• unwise
• harebrained
• unbelievable
• imbecile
• unreal
• unrealistic
• illogical
• loony
• wacky
• simpleminded
• witless
• brainless
• daffy
• nutty
• kooky
• jerky
• cuckoo
• far-fetched
• half-baked
• senseless
• daft
• cockeyed
• screwball
• half-witted
• weak-minded
• balmy
• dotty

Antonyms & Near Antonyms

• serious
• earnest
• solemn
• reasonable
• logical
• realistic
• conceivable
• rational
• credible
• sensible
• believable

Example Sentences

Recent Examples of preposterous

But some critics found the book as preposterous as the Betty Crocker cake mixes the Prices tote with them across the Atlantic. — Casey Cep, New Yorker, 21 Sep. 2026

As the story became an international sensation, theories toggled between the preposterous and the merely unlikely. — Jon Wertheim, CBS News, 20 Sep. 2026

Fazio’s announcement undermined one more preposterous claim by the shrinking figure that is Diamantis. — Kevin Rennie, Hartford Courant, 19 Sep. 2026

During his first tenure, Verrett represented the very type of behavior Magnus had spent the past few years weeding out, including deranged posts, unprofessional direct messages to reporters, and preposterous race talk. — Bobby Burack Outkick, FOXNews.com, 9 Sep. 2026