What does "illegitimate" mean?

Additional senses

1. 2.Not legitimately deduced or inferred; illogical; as, an illegitimate inference.
2. 3.Not authorized by good usage; not genuine; spurious; as, an illegitimate word. Illegitimate fertilization, or Illegitimate union (Bot.), the fertilization of pistils by stamens not of their own length, in heterogonously dimorphic and trimorphic flowers. Darwin.
3. 4.To render illegitimate; to declare or prove to be born out of wedlock; to bastardize; to illegitimatize. The marriage should only be dissolved for the future, without illegitimating the issue. Bp. Burnet.