heterologous vs mixed

heterologous

adj
  • Having different relationships or different elements 

  • Of, or relating to different species 

mixed

adj
  • Having two or more separate aspects. 

  • Including both male(s) and female(s). 

  • Not completely pure, tainted or adulterated. 

  • Stemming from two or more races or breeds 

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