pucker vs tighten

pucker

verb
  • To pinch or wrinkle; to squeeze inwardly, to dimple or fold. 

noun
  • A state of perplexity or anxiety; confusion; bother; agitation. 

  • A fold or wrinkle. 

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 pucker and tighten occurred in a corpus of books? (source: Google Ngram Viewer )