co-ed vs half-breed

co-ed

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

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

half-breed

adj
  • Having dual heritage; having mixed racial parentage or ancestry. 

  • Hybridized; having one purebred parent; descended from parents of different breeds or with different traits. 

noun
  • A person of mixed racial parentage or ancestry, especially one of mixed white and American Indian parentage (metis, métis, Metis, Métis; mestizo). 

  • A hybrid animal or plant. 

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