Source : Webster's Revised Unabridged Dictionary (1913)

Mongrel \Mon"grel\, n. [Prob. shortened fr. mongrel, and akin to
   AS. mengan to mix, and E. mingle. See {Mingle}.]
   The progeny resulting from a cross between two breeds, as of
   domestic animals; anything of mixed breed. --Drayton.

Mongrel \Mon"grel\, a.
   1. (Zo["o]l.) Not of a pure breed.

   2. Of mixed kinds; as, mongrel language.

Source : WordNet®

mongrel
     n 1: derogatory term for a variation that is not genuine;
          something irregular or inferior or of dubious origin;
          "the architecture was a kind of bastard suggesting
          Gothic but not true Gothic" [syn: {bastard}]
     2: an inferior dog or one of mixed breed [syn: {cur}, {mutt}]