- Born to unmarried parents.
"an illegitimate child"
- (botany) Involving the fertilization of pistils by stamens not of their own length, in heterogonously dimorphic and trimorphic flowers.
- Illegal; against the law.
- Not authorized by good usage; not genuine; spurious.
"an illegitimate word"
- Illogical; incorrectly deduced.
"an illegitimate inference"