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

Synonyms & Similar Words

Relevance

Antonyms & Near Antonyms

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.

Recent Examples of irrational The industrial revolutions of the past produced enormous value alongside bankruptcies, dislocations, and periods of irrational exuberance. — Brian Solis, Forbes.com, 5 Oct. 2026 If anyone can reconstruct Apéry’s reasoning, the odd values of zeta may finally be proven irrational. — Lyndie Chiou, Scientific American, 2 Oct. 2026 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 See All Example Sentences for irrational

Recent Examples of Synonyms for irrational

Adjective

With 20th Television increasingly focused on supplying Disney platforms, integrating the two areas would not be unreasonable.

— Nellie Andreeva, Deadline, 5 Nov. 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

Well, yes, this Court is an illegitimate Court on a number of levels.

— David Remnick, New Yorker, 30 Oct. 2026
Some people who file illegitimate disputes are simply looking to take advantage of the system and were never good customers to begin with.

— Arthur Zaczkiewicz, Footwear News, 30 Oct. 2026