The Collaborative International Dictionary of English v.0.48:

Homonymous \Ho*mon"y*mous\, a. [L. homonymus, Gr. ?; ? the same
   + ?, for ? name; akin to E. name.]
   1. Having the same name or designation; standing in the same
      relation; -- opposed to heteronymous.
      [1913 Webster]

   2. Having the same name or designation, but different meaning
      or relation; hence, equivocal; ambiguous.
      [1913 Webster]

WordNet (r) 3.0 (2006):

homonymous
    adj 1: of or related to or being homonyms [syn: homonymic,
           homonymous]