metonym vs quasi-synonym

metonym

noun
  • A word that names an object from a single characteristic of it or of a closely related object; a word used in metonymy. 

  • A concept, idea, or word used to represent, typify, or stand in for a broader set of ideas. 

quasi-synonym

noun
  • Synonym of near-synonym 

How often have the words metonym and quasi-synonym occurred in a corpus of books? (source: Google Ngram Viewer )