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 If people believe regulatory caution invalidates every legal claim, courts may look irrational. — Alex Smolak, STAT, 27 June 2026 Does pot make users irrational? — Morgan Marietta, The Conversation, 26 June 2026 Naturally, the mobile app includes a heaping helping of generative AI that aims to make sense of irrational financial markets. — Ryan Whitwam, ArsTechnica, 25 June 2026 Economist Hyman Minsky spent his career explaining how irrational behavior produces fragility and instability in capitalist systems. — Hersh Shefrin, Forbes.com, 23 June 2026 See All Example Sentences for irrational

Recent Examples of Synonyms for irrational

Adjective

His certification is temporarily suspended due to excessive or unreasonable force from the incident, according to the California Commission on Peace Officer Standards and Training.

— Theresa Clift, Sacbee.com, 7 July 2026
Your request for back-to-back weeks off at the last minute is unreasonable.

— Harriette Cole, Mercury News, 3 July 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

That difference suggests that the government sees this extension of patent rights as an illegitimate way for a company to exclude other companies from competing.

— Julie Dawson, The Conversation, 23 June 2026
Some fraudsters run an illegitimate DME company and get a doctor to prescribe the equipment.

— Janice Neumann, Chicago Tribune, 16 June 2026