co-ed vs heterologous

co-ed

adj
  • Of any location, that mixes males and females. 

  • Of an educational institution, that teaches both males and females. 

heterologous

adj
  • Having different relationships or different elements 

  • Of, or relating to different species 

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