Synonyms and Antonyms of rational
1 having the ability to reason <human beings are rational creatures> Synonyms intelligent, reasonable, reasoning, thinking Related Words analytic (or analytical), logical; brainy, cerebral, highbrow, highbrowed, intellectual; cognitional, cognitive, mental; levelheaded, practical, sane, sensible, sober Near Antonyms brainless, dense, doltish, dopey (also dopy), dorky [slang], dull, dumb, fatuous, half-witted, mindless, obtuse, senseless, slow, stupid, thickheaded; fallacious, groundless, illogical, invalid, nonsensical Antonyms irrational, nonrational, nonthinking, unintelligent, unreasonable, unreasoning, unthinking
2 according to the rules of logic <insisted there was a rational explanation for the strange creaking noises and that there were no such things as ghosts> Synonyms analytic (or analytical), coherent, consequent, good, logical, reasonable, sensible, sound, valid, well-founded, well-groundedRelated Words a posteriori, a priori, syllogistic; cognitive, empirical (also empiric); defendable, defensible, justifiable, maintainable, supportable, sustainable, tenableNear Antonyms casuistic (or casuistical), eristic (also eristical), fallacious, misleading, sophistic (or sophistical), specious; unarticulated; unscientific; absurd, cockeyed, crazy, daffy, fatuous, half-baked, half-witted, harebrained, insane, loony (also looney), mad, nonsensical, nutty, preposterous, simpleminded, stupid, weak-minded, witless; senseless, thoughtless; uncompelling, unconvincingAntonyms illegitimate, illogical, incoherent, inconsequent, inconsequential, invalid, irrational, unreasonable, unsound, weak
3 based on sound reasoning or information <betting all of your savings on the lottery is not a rational move> Synonyms commonsense, commonsensible, commonsensical, firm, hard, informed, just, justified, levelheaded, logical, good, reasonable, reasoned, sensible, sober, solid, valid, well-foundedRelated Words actual, real, true; certain, sure; certified, validated, verified; confirmed, corroborated, substantiated; cogent, convincing; colorable, credible, plausibleNear Antonyms unsubstantiated, unsupported, unwarranted; flimsy, implausible, unconvincing, weak; fallacious, false, misguided, misledAntonyms groundless, illogical, invalid, irrational, nonrational, nonsensical, nonvalid, unfounded, uninformed, unjustified, unreasonable, unreasoned, unsound
Seen and Heard
What made you want to look up rational? Please tell us where you read or heard it (including the quote, if possible).