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

But Michael Edney, who worked at the OLC under Bush, said the opinion’s reading of executive privilege was not unreasonable, given the importance that some presidents place on outside consultation.

— Perry Stein, Washington Post, 18 Oct. 2026
Both sides have accused each other of being unreasonable and of ignoring practical concerns about voting and election security, though in very different ways.

— Kevin Rector, Los Angeles Times, 17 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

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
Saman admitted to purchasing much of his inventory from brokers or middlemen, which the department identified as illegitimate distributors of the brands.

— Glenn Taylor, Footwear News, 8 Oct. 2026