Synonyms of fallacious

fallacious

adjective

fə-ˈlā-shəs 

1

as in unreasonable

not using or following good reasoning

it's fallacious to say that something must exist because science hasn't proven its nonexistence

Synonyms & Similar Words

• unreasonable
• irrational
• unreasoning
• illegitimate
• misleading
• unreasoned
• illogical
• absurd
• weak
• foolish
• silly
• invalid
• unsound
• nonrational
• inconsequent
• inconsequential
• specious
• weird
• meaningless
• inconsistent
• sophistic
• misguided
• unusual
• odd
• strange
• asinine
• unconsidered
• nonsensical
• preposterous
• random
• insane
• eristic
• unconvincing
• surreal
• ill-advised
• half-baked
• inexplicable
• disorganized
• disordered
• mad
• wacky
• senseless
• unexplainable
• nutty
• rambling
• reasonless
• unaccountable
• peculiar
• Kafkaesque

Antonyms & Near Antonyms

• reasonable
• logical
• valid
• rational
• sound
• wise
• sensible
• justified
• reasoned
• well-founded
• sane
• enlightened
• sober
• informed
• plausible
• persuasive
• just
• well-grounded
• convincing
• compelling
• clear
• commonsense
• true
• solid
• credible
• certain
• organized
• cogent
• satisfying
• sure
• demonstrated
• ordered
• confirmed
• established
• substantiated
• validated
• corroborated

2

as in misleading

tending or having power to deceive

consumers who harbor the fallacious belief that credit-card spending will never catch up with them

Synonyms & Similar Words

• misleading
• deceptive
• false
• incorrect
• specious
• delusive
• ambiguous
• deceitful
• deceiving
• beguiling
• inaccurate
• delusory
• fraudulent
• subtle
• deluding
• crooked
• cunning
• dishonest
• perplexing
• wrong
• trick
• mendacious
• puzzling
• lying
• wily
• treacherous
• confounding
• tricky
• slick
• underhanded
• untrustworthy
• crafty
• sneaky
• artful
• spurious
• devious
• untruthful
• shifty
• artificial
• insidious
• counterfeit
• shady
• subtile
• distracting
• sly
• forged
• bogus
• duplicitous
• underhand
• faithless
• perfidious
• foxy
• bewildering
• fake
• trickish
• evasive
• hypocritical
• guileful
• feigned
• dissembling
• equivocal
• phony
• sham
• insincere
• ambidextrous
• jive
• knavish
• circuitous
• sneaking
• backhanded
• fast
• defrauding
• double-dealing
• two-faced
• left-handed

Antonyms & Near Antonyms

• straightforward
• forthright
• plain
• direct
• open
• outspoken
• frank
• candid
• straight
• illuminating
• explanatory
• aboveboard
• nondeceptive
• revealing
• clarifying
• plainspoken
• truthful
• revelatory
• openhearted
• free-spoken
• elucidative
• trustworthy
• honest
• foursquare

Example Sentences

Recent Examples of fallacious

There is a widespread but fallacious perception that India's tariffs are inordinately high. — Mohan Kumar, MSNBC Newsweek, 31 Aug. 2025

The same economists who believe in the same fallacious economic notions? — John Tamny, Forbes.com, 6 July 2025

That will in turn spread on social media, which often plays a disproportional role in boosting these disinformation efforts by providing nearly unlimited platforms for unfiltered content and fallacious and deceptive claims. — Peter Suciu, Forbes, 23 Dec. 2024

There might be a bigger market for these products, and more consumers might be immune to the fallacious argument that they’re overly processed, if more people were persuaded of the ills of factory farming. — Kenny Torrella, Vox, 7 Dec. 2018

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