Illegitimate1. (a.) Unlawfully begotten; as, an illegitimate child or illegitimate gains.
2. (a.) Not according to law; not regular or authorized; unlawful; improper.
3. (a.) Not legitimately deduced or inferred; illogical; as, an illegitimate inference.
4. (a.) Not authorized by good usage; not genuine; spurious; as, an illegitimate word.
5. (v. t.) To render illegitimate; to declare or prove to be born out of wedlock; to bastardize; to illegitimatize.
Thesaurus Entries
actionable, affected, against the law, anarchic, anarchistic, anomic, apocryphal, artificial, assumed, bantling, bar sinister, baseborn, bastard, bastard child, bastardy, black-market, bogus, bootleg, brummagem, by-blow, chargeable, colorable, colored, contraband, contrary to law, counterfeit, counterfeited, criminal, distorted, dressed up, dummy, embellished, embroidered, ersatz, factitious, fake, faked, FALSE, falsified, fatherless, feigned, felonious, fictitious, fictive, flawed, garbled, illegal, illegitimacy, illegitimate child, illicit, imitation, impermissible, improper, incorrect, invalid, irregular, junky, justiciable, lawless, love child, make-believe, man-made, misbegotten, miscreated, mock, natural, nonconstitutional, nonlegal, nonlicit, outlaw, outlawed, perverted, phony, pinchbeck, pretended, pseudo, punishable, put-on, quasi, queer, self-styled, sham, shoddy, simulated, so-called, soi-disant, spurious, supposititious, synthetic, tin, tinsel, titivated, triable, twisted, unallowed, unauthentic, unauthorized, unconstitutional, under-the-counter, under-the-table, ungenuine, unlawful, unnatural, unofficial, unreal, unstatutory, unwarrantable, unwarranted, warped, wrongful