CASE vs roofing

CASE

noun
  • coatings, adhesives, sealants and elastomers. 

  • computer-aided software engineering. 

roofing

noun
  • Material used on the outside of a roof, such as shingles. 

  • The process of constructing a roof or roofs. 

  • A way of travel which consists in clambering over the roofs of skyscrapers. 

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