man-eater vs side piece

man-eater

noun
  • A seductive dangerous woman, often readily taking and discarding male romantic partners. 

  • A cannibal; a human that eats other humans. 

  • An animal that attacks and kills humans for food, such as certain tigers or sharks; any animal that consumes human flesh. 

side piece

noun
  • A mistress; a woman with whom a man carries on a physical affair (not emotional affair) without having the intention of forming a serious relationship. 

How often have the words man-eater and side piece occurred in a corpus of books? (source: Google Ngram Viewer )