Source : Webster's Revised Unabridged Dictionary (1913)

Miscegenation \Mis`ce*ge*na"tion\, n. [L. miscere to mix + the
   root of genus race.]
   A mixing of races; amalgamation, as by intermarriage of black
   and white.

Source : WordNet®

miscegenation
     n : reproduction by parents of different races (especially by
         white and non-white persons) [syn: {crossbreeding}, {interbreeding}]