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 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 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 See All Example Sentences for irrational

Recent Examples of Synonyms for irrational

Adjective

On the surface, paying as low as 24 cents for an hour of streaming game time doesn’t sound completely unreasonable.

— Kyle Orland, ArsTechnica, 21 Oct. 2026
If Putin rejects the framework — or, more likely, demands unreasonable changes — then the world will at least know who blocked the fledgling peace effort.

— David Ignatius, Washington Post, 21 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