crossmate vs outcross

crossmate

verb
  • To mate individuals of different species, breeds, etc. 

outcross

verb
  • to crossbreed different strains of a plant or animal. 

noun
  • A plant or animal produced by such methods. 

  • The introduction of unrelated breeding stock to an existing population, especially one which is inbred or homogeneous. 

How often have the words crossmate and outcross occurred in a corpus of books? (source: Google Ngram Viewer )