clunch vs paper clay

clunch

noun
  • A traditional building material mostly made of chalk or clay. 

verb
  • To grasp firmly; clench. 

paper clay

noun
  • Clay mixed with shredded paper or other fibres, valued for its strength and light weight in the production of large ceramic works. 

  • A kind of uniformly light-coloured clay composed of fine particles, used in the production of paper and wallpaper; kaolin. 

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