noun (n)

• (genetics) the act of mixing different species or varieties of animals or plants and thus to produce hybrids(noun.act)

  Synonym:
  cross, crossing, hybridisation, hybridization, hybridizing, interbreeding
  

  source: wordnet30
• reproduction by parents of different races (especially by white and non-white persons)(noun.act)

  Synonym:
  interbreeding, miscegenation
  

  source: wordnet30