buckram vs tighten

buckram

verb
  • To stiffen with or as if with buckram. 

noun
  • A coarse cloth of cotton, linen or hemp, stiffened with size or glue, used in bookbinding to cover and protect the books, in garments to keep them in the form intended, and for wrappers to cover merchandise. 

  • A plant, Allium ursinum, also called ramson, wild garlic, or bear garlic. 

tighten

verb
  • To make tighter. 

  • To raise short-term interest rates. 

  • To make money harder to borrow or obtain. 

  • To become tighter. 

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