The Collaborative International Dictionary of English v.0.48:

Monstrosity \Mon*stros"i*ty\ (m[o^]n*str[o^]s"[i^]*t[y^]), n.;
   pl. Monstrosities (m[o^]n*str[o^]s"[i^]*t[i^]z). [Cf. F.
   monstruosit['e]. See Monstrous.]
   The state of being monstrous, or out of the common order of
   nature; that which is monstrous; a monster. --South.
   [1913 Webster]

         A monstrosity never changes the name or affects the
         immutability of a species.               --Adanson
                                                  (Trans.).
   [1913 Webster]