Synonyms of irrational in English:

irrational


See US English definition of irrational

See UK English definition of irrational

See Spanish definition of irracional

adjective

1‘she told herself that it was an irrational fear’

SYNONYMS
unreasonable, illogical, groundless, baseless, unfounded, unjustifiable, unsound
absurd, ridiculous, ludicrous, silly, foolish, senseless, nonsensical, laughable, idiotic, stupid, wild
untenable, implausible, unscientific, arbitrary
informal crazy, mad
British informal barmy, daft
North American informal backasswards
ANTONYMS

rational, logical