illegitimate

1 born to a father and mother who are not married despite being illegitimate, Alexander Hamilton rose to greatness Synonyms baseborn, bastard, misbegotten, natural, spurious, supposititious, unfathered Related Words fatherless, motherless; nameless; adopted, orphaned Antonyms legitimate

2 contrary to or forbidden by law an illegitimate use of campaign contributions for personal expenses Synonyms criminal, felonious, illegal, illicit, lawless, unlawful, wrongfulRelated Words bad, evil, immoral, shameful, sinful, unethical, wicked, wrong; blamable, blameworthy, censurable, reprehensible; banned, barred, contraband, criminalized, disallowed, discouraged, forbidden, interdicted, outlawed, prohibited, proscribed; adulterine, bootleg, unauthorized, unlicensed, unsanctioned; under-the-counter, under-the-table; corrupt, unprincipled, unscrupulous, villainousNear Antonyms ethical, good, just, principled, right, righteous, virtuous; allowed, permitted; authorized, licensed; approved, endorsed (also indorsed), sanctioned; abetted, encouraged, promoted, suggested, supported; correct, decent, decorous, proper, seemlyAntonyms lawful, legal, legitimate

3 not using or following good reasoning made several illegitimate inferences Synonyms fallacious, illogical, 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