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Showing results for irrational. Search instead for irrational/4.
Definitions

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.

However, she said she had experienced fear and irrational guilt after Eliza's diagnosis.

From BBC • Mar. 22, 2026

While the motives that drive a knight are often human, political, or both, the logic is as miraculous and irrational as a muddy hedge knight crawling out from under a fallen dragon.

From Salon • Feb. 25, 2026

Freight was another sector that some analysts said was subjected to irrational AI fears last week.

From MarketWatch • Feb. 17, 2026

Knowing they’ve lost the chance at a fortune, people will sometimes take irrational risks to make it back.

From The Wall Street Journal • Feb. 9, 2026

It would be hard to keep the secret of the irrational hidden from a people so obsessed with geometry and ratios.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.