unsubstantiated

having no basis in reason or fact an unsubstantiated claim that was thrown out of court Synonyms baseless, foundationless, invalid, nonvalid, unfounded, unreasonable, groundless, unsupported, unwarrantedRelated Words illogical, irrational, nonlogical, unconscionable, unsound; fallacious, false, misled, wrong; gratuitous, uncalled-for, unnecessary; flimsy, implausible, misleading, specious, unconvincing, untenable, weak; ill-advised, unreasoned; inconsistent; absurd, asinine, brainless, crackpot, crazy, fatuous, foolish, half-witted, harebrained, meaningless, nonsensical, preposterous, senseless, silly, simpleminded, stupid, unwise; insane, lunatic, mad, nutty, wacky (also whacky)Near Antonyms certified, validated, verified; confirmed, corroborated; informed, logical, rational; commonsense, sane, sensible, sober, wise; actual, genuine, real, true; certain, sure; clear, cogent, compelling, convincing, credible, persuasive, plausible, satisfying, solid, soundAntonyms good, hard, just, justified, reasonable, reasoned, substantiated, valid, well-founded, well-grounded