Illegitimate

1. Not legitimately deduced or inferred; illogical; as, an illegitimate inference.
2. Not authorized by good usage; not genuine; spurious; as, an illegitimate word.
3. Not according to law; not regular or authorized; unlawful; improper.
4. Unlawfully begotten; born out of wedlock; bastard; as, an illegitimate child.
5. To render illegitimate; to declare or prove to be born out of wedlock; to bastardize; to illegitimatize.