cross-breed vs crossmate

cross-breed

verb
  • To breed separate strains of the same species in order to create new traits. 

  • To breed members of similar albeit distinct species, for example, horse X donkey = mule 

adj
  • Of or pertaining to the offspring produced by cross-breeding. 

noun
  • An offspring produced by cross-breeding. 

crossmate

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

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