irrational

not using or following good reasoning it's irrational to think that you can continue to consume an excess of calories and not gain weight Synonyms fallacious, illegitimate, inconsequent, inconsequential, invalid, illogical, nonrational, unreasonable, unreasoning, unsound, weakRelated Words eristic (also eristical), misleading, sophistic (or sophistical), specious; half-baked, ill-advised, misguided, unconsidered, unreasoned; inconsistent; absurd, asinine, foolish, meaningless, nonsensical, preposterous, reasonless, senseless, silly; Kafkaesque, odd, peculiar, strange, surreal, unusual, weird; insane, mad, nutty, wacky (also whacky); disordered, disorganized, rambling, random; unconvincing; inexplicable, unaccountable, unexplainableNear Antonyms commonsense, sane, sensible, sober, wise; enlightened, informed, just, justified, reasoned; ordered, organized; clear, cogent, compelling, convincing, credible, persuasive, plausible, satisfying, solid; certain, sure, true; confirmed, corroborated, demonstrated, established, substantiated, validatedAntonyms logical, rational, reasonable, sound, valid, well-founded, well-grounded