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, or Illegitimate union Bot., the fertilization of pistils by stamens not of their own length, in heterogonously dimorphic and trimorphic flowers.
Il·le·git·i·mate v. t. [imp. & p. p. Illegitimated p. pr. & vb. n. Illegitimating.] 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.
adj 1: contrary to or forbidden by law; "an illegitimate seizure of
power"; "illicit trade"; "an outlaw strike"; "unlawful
measures" [syn: illicit, outlaw(a), outlawed, unlawful]
2: of marriages and offspring; not recognized as lawful [ant: legitimate]
n : the illegitimate offspring of unmarried parents [syn: bastard,
by-blow, love child, illegitimate child, whoreson]