The Collaborative International Dictionary of English v.0.48:

falcon-gentil \fal"con-gen`til\, falcon-gentle \falcon-gentle\,
   n. [F. faucon-gentil. See Falcon, and Genteel.]
   1. (Zool.) any female falcon; especially
      [PJC]

   2. (Zool.) a female peregrine falcon (Falco peregrinus).

   Syn: falcon-gentil.
        [WordNet 1.5]

   3. (Zool.) The female or young of the goshawk (Accipiter
      gentilis, formerly Astur palumbarius).
      [1913 Webster]

WordNet (r) 3.0 (2006):

falcon-gentil
    n 1: female falcon especially a female peregrine falcon [syn:
         falcon-gentle, falcon-gentil]