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 The fact, in other words, that there often isn’t a right answer or a clear victor—and that rational people are subject to irrational forces within and above them. — Max Norman, Harpers Magazine, 22 Sep. 2026 Our simple equation, for example, has the solutions and , which are irrational; their digits begin and keep going forever without repeating. — Quanta Magazine, 9 Sep. 2026 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 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 See All Example Sentences for irrational

Recent Examples of Synonyms for irrational

Adjective

That triggers First Amendment protection, and that means there cannot be viewpoint discrimination or unreasonable restrictions that are inconsistent with the speech activities imposed on the journalists.

— Ted Johnson, Deadline, 30 Oct. 2026
Frimpong concluded that plaintiffs were likely to prove the practice violated the 4th Amendment’s protection against unreasonable seizures and the 5th Amendment’s guarantee of equal protection.

— Brittny Mejia, Los Angeles Times, 29 Oct. 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

Finally, the article argues that the federal lawsuit threatens state control over election administration and could fuel further claims that election results are illegitimate.

— Los Angeles Times, Los Angeles Times, 20 Oct. 2026
An adult child can claim authority over the meaning of a life without proving that everything inherited is therefore illegitimate.

— Literary Hub, Literary Hub, 9 Oct. 2026