invalid

1 having no legal or binding force the treaty is invalid once one side violates it Synonyms bad, inoperative, invalid, nonbinding, nonvalid, nugatory, null and void, voidRelated Words illegal; useless, worthless; ineffective, ineffectualNear Antonyms legal; workingAntonyms binding, good, valid

2 not being in agreement with what is true that's an invalid assumption on your part Synonyms erroneous, inaccurate, incorrect, inexact, invalid, off, unsound, untrue, untruthful, wrongRelated Words counterfactual; specious, spurious; deceptive, delusive, delusory, distorted, fallacious, fictitious, illusory, misleading; amiss, askew, awry; deceitful, dishonest, fraudulent, lying, mendacious; unconfirmed, unproven, untested; fabricated, invented, made-up, trumped-upNear Antonyms confirmed, demonstrated, established, proven, tested; faultless, flawless, impeccable, letter-perfect, perfectAntonyms accurate, correct, errorless, exact, factual, precise, proper, right, sound, true, valid, veracious

3 not using or following good reasoning an argument which has one untrue premise is invalid Synonyms fallacious, illegitimate, inconsequent, inconsequential, invalid, irrational, 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

4 having no basis in reason or fact an invalid claim that can be easily disproved by the facts Synonyms baseless, foundationless, invalid, nonvalid, unfounded, unreasonable, unsubstantiated, 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