1. (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.

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