IRRATIONAL Synonyms: 89 Similar and Opposite Words

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

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Recent Examples of irrational The bullish argument goes that earnings season went better than expected, so the rally isn’t irrational. —

Allison Morrow, CNN Money, 13 May 2026 His deep dive into the genre left him with some pet peeves, not least the irrational or simply implausible behavior of many horror-movie protagonists. —

Alex Barasch, New Yorker, 11 May 2026 Evans and his backers were rational actors inside an irrational system. —

Big Think, 1 May 2026 His new film follows a young musician with gerontophobia, whose irrational fear of ageing and death sees her neglect her dying parents. —

Melanie Goodfellow, Deadline, 30 Apr. 2026 See All Example Sentences for irrational

Recent Examples of Synonyms for irrational

Adjective

Last year’s conference-final loss to the Florida Panthers — an ugly result for an overmatched roster that had spent the regular season outkicking its coverage, maximizing its performance and raising expectations to an unreasonable level — is on that ledger, too.

— Sean Gentille, New York Times, 28 May 2026
That lingering inventory, which has drawn criticism from fans who believe the list prices are unreasonable, is a principal feature of the governing body’s ticket pricing strategy.

— Sara Germano, Sportico.com, 28 May 2026