[syn: illegitimately, out of wedlock]
The Collaborative International Dictionary of English v.0.48:
Illegitimately \Il`le*git"i*mate*ly\, adv.
   In a illegitimate manner; unlawfully.
   [1913 Webster]
WordNet (r) 3.0 (2006):
illegitimately
    adv 1: in a manner disapproved or not allowed by custom; "He
           acted illegitimately when he increased the rent fourfold"
           [syn: illegitimately, illicitly] [ant: lawfully,
           legitimately, licitly]
    2: of biological parents not married to each other; "this child
       was born illegitimately" [syn: illegitimately, out of
       wedlock] [ant: legitimately]