Adjective illegitimate has 2 senses
  1. illegitimate, illicit, outlaw, outlawed, unlawful - contrary to or forbidden by law; "an illegitimate seizure of power"; "illicit trade"; "an outlaw strike"; "unlawful measures"
    Antonym: legal (indirect, via illegal)
  2. illegitimate - of marriages and offspring; not recognized as lawful
    legitimate, lawfully-begotten, morganatic, left-handed, true, lawful, rightful
,Noun illegitimate has 1 sense
  1. bastard, by-blow, love child, illegitimate child, illegitimate, whoreson - the illegitimate offspring of unmarried parents
    --1 is a kind of offspring, progeny, issue