rational opposite

What Is The Opposite Word Of Rational? illogicalgroundless invalidirrational unfounded unjustified unreasoned fallacious thoughtless unjustifiable What is the opposite of rationality? rationality. Antonyms: aberration, alienation, craziness, delirium, dementia, derangement, frenzy, hallucination, insanity, lunacy, madness, mania, monomania. Synonyms: clearness, good sense, lucidity, sanity. What is the opposite of the rational? illogicalgroundless invalidirrational unfounded unjustified unreasoned fallacious