Synonyms of irrational

irrational

adjective

i-ˈra-sh(ə-)nəl 

as in unreasonable

not using or following good reasoning

it's irrational to think that you can continue to consume an excess of calories and not gain weight

Synonyms & Similar Words

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

Antonyms & Near Antonyms

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

Example Sentences

Recent Examples of irrational

As a result, the argument goes, today's spending is irrational because the hardware would need to be replaced too frequently to generate an attractive return on investment, known as ROI. — CNBC, 12 Aug. 2026

The policy is particularly irrational when applied to bicyclists and pedestrians. — Jeffrey T. Donner, The Orlando Sentinel, 9 Aug. 2026

For all the film focuses on Carlson’s irrational attempts to peg the murder on gay people, the actual gay man Tom disappears from the narrative for long periods of time. — Alison Foreman, IndieWire, 31 July 2026

In both cases, cheap credit fueled the irrational exuberance. — Annie Lowrey, The Atlantic, 21 July 2026