clench vs sealskin

clench

noun
  • A seal that is applied to formed thin-wall bushings. 

  • A tight grip. 

  • A local chapter of the Church of the SubGenius parody religion. 

verb
  • To close tightly. 

  • To grip or hold fast. 

sealskin

noun
  • A type of fabric made from the skin of seals. 

  • An item of clothing made from sealskin (whether real or imitation). 

  • Any fabric manufactured to resemble sealskin. 

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