IRRATIONAL Synonyms: 89 Similar and Opposite Words

irrational

adjective

i-ˈra-sh(ə-)nəl

Definition of irrational

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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Example Sentences

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Recent Examples of irrational An irrational holding on to the possibility of a comeback, if that was the word if no one noticed you’d retired in the first place. — Literary Hub, 17 July 2026 Their ideas about it were often steeped in stereotypes suggesting that Buddhists were irrational and childish in their thinking. — Livia Gershon, JSTOR Daily, 7 July 2026 Scammers often use isolation tactics in phone calls to panic the listener and rush them into making irrational choices that often have financial costs. — Ella Moore july 2, Miami Herald, 2 July 2026 Thanks to this fit of irrational exuberance, the NBA realized the benefits of cap smoothing and more-friendly contract-extension language in the collective bargaining agreement. — John Hollinger, New York Times, 1 July 2026 See All Example Sentences for irrational

Recent Examples of Synonyms for irrational

Adjective

The standard is very low, and that is 'more probable than not' that this child may have been put in an unreasonable risk of harm.

— Erin Moriarty, CBS News, 9 Aug. 2026
In such an environment, Fundstrat’s Tom Lee has argued that the S & P 500 can climb to 8,000 over the next few weeks, a level that is not too unreasonable given that the broader index was last trading around 7,750 — only 3% away.

— Sarah Min, CNBC, 7 Aug. 2026

Definition of unreasonable

Adjective

But in each event—in the living act, the undoubted deed—there, some unknown but still reasoning thing puts forth the mouldings of its features from behind the unreasoning mask.

— Literary Hub, Literary Hub, 6 July 2026
Roosevelt surely understood that nameless, unreasoning, unjustified fear cannot be eradicated.

— New York Times, New York Times, 9 June 2026

Definition of unreasoning

Adjective

But that’s forcing them to wrestle with the idea that any action taken by a party is illegitimate, anti-democratic rigging — something the other team can use to depress the base.

— David Weigel, semafor.com, 22 July 2026
Signature-matching efforts sometimes disqualify more legitimate than illegitimate ballots.

— Jeremy Kohler, ProPublica, 15 July 2026