caulking vs wafer

caulking

noun
  • A sealing material used to seal joints between heterogeneous materials in many kinds of construction and manufacture. 

wafer

noun
  • A soft disk originally made of flour, and later of gelatin or a similar substance, used to seal letters, attach papers etc. 

  • A thin disk of consecrated unleavened bread used in communion. 

  • A light, thin, flat biscuit/cookie. 

  • A thin disk of silicon or other semiconductor on which an electronic circuit is produced. 

verb
  • To seal or fasten with a wafer. 

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