If you describe someone's feelings and behaviour as irrational, you mean they are not based on logical reasons or clear thinking. adj
(=unreasonable) (Antonym: rational)
...an irrational fear of science.
irrationally adv ADV with v, ADV adj, ADV with cl
My husband is irrationally jealous over my past loves.
...the irrationality of his behaviour.
Translation English Cobuild Collins Dictionary
1 absurd, crackpot (informal) crazy, foolish, illogical, injudicious, loopy (informal) nonsensical, preposterous, silly, unreasonable, unreasoning, unsound, unthinking, unwise
2 aberrant, brainless, crazy, demented, insane, mindless, muddle-headed, raving, senseless, unstable, wild
1 circumspect, judicious, logical, rational, reasonable, sensible, sound, wise
English Collins Dictionary - English synonyms & Thesaurus
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