clench vs girth strap

clench

noun
  • A tight grip. 

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

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

verb
  • To close tightly. 

  • To grip or hold fast. 

girth strap

noun
  • A cinch or a girth: a strap round the belly of an animal used to hold a saddle in place. 

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