chromo vs side chick

chromo

noun
  • A prostitute. 

  • A color print produced by chromolithography. 

adj
  • Of or relating to the chromodomain, a protein structural domain associated with chromatin production 

side chick

noun
  • A mistress; a woman one dates in addition to one's girlfriend or wife, usually in secret. 

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