figment of one's imagination vs yarn

figment of one's imagination

noun
  • A product of the imagination. 

yarn

noun
  • A story, a tale, especially one that is incredible. 

  • A twisted strand of fiber used for knitting or weaving. 

  • Bundles of fibers twisted together, and which in turn are twisted in bundles to form strands, which in their turn are twisted or plaited to form rope. 

verb
  • To tell a story or stories, especially one that is lengthy or unlikely to be true. 

How often have the words figment of one's imagination and yarn occurred in a corpus of books? (source: Google Ngram Viewer )