Mistress vs hinny

Mistress

noun
  • Used as the title of a female dominant. 

hinny

noun
  • A term of endearment usually for women. 

  • The hybrid offspring of a stallion (male horse) and a she-ass (female donkey). 

verb
  • To whinny 

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