Il′le‐git″i‐mate (?), a. 1. Not according to law; not regular or authorized; unlawful; improper.
2. Unlawfully begotten; born out of wedlock; bastard; as, an illegitimate child.
3. Not legitimately deduced or inferred; illogical; as, an illegitimate inference.
4. Not authorized by good usage; not genuine; spurious; as, an illegitimate word.
Illegitimate fertilization, orIllegitimate union(Bot.), the fertilization of pistils by stamens not of their own length, in heterogonously dimorphic and trimorphic flowers. Darwin.