irrational

[ih-rash-uh-nl, -rash-nl] / ɪˈræʃ ə nl, -ˈræʃ nl /

ADJECTIVE

illogical, senseless

Synonyms

STRONGEST

aberrant absurd crazy foolish incoherent insane preposterous ridiculous stupid unreasonable unsound unwise wrong

STRONG

invalid loony raving silly wild

WEAK

brainless cockamamie delirious demented disconnected disjointed distraught fallacious flaky freaky injudicious kooky mad mindless nonsensical nutty off-the-wall reasonless sophistic specious unreasoning unstable unthinking wacky

Antonyms

STRONGEST

balanced logical rational realistic reasonable responsible sane sensible serious smart sound thoughtful well wise

WEAK

reflective stable

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

In their legal claim, the group alleges that Vodafone – which has more than 350 franchise stores – made business decisions in "irrational, arbitrary" ways.

From BBC • May 5, 2026

We’re clinging to that belief but will concede that it may be irrational.

From Slate • May 2, 2026

Individual investors have been pulling money out of private-credit funds at a rising pace this year, a phenomenon fund managers have blamed on irrational fears fanned by the media.

From The Wall Street Journal • Apr. 24, 2026

Asked later about stress levels on the ground, NASA's associate administrator said "it's impossible to say you don't have any irrational fears left."

From Barron's • Apr. 10, 2026

Because as soon as you start hoping something’s going to happen, you get irrational.

From "We'll Fly Away" by Bryan Bliss

Vocabulary lists containing irrational

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