crochet vs pin down

crochet

verb
  • To make (a piece of) needlework using a hooked needle; to make interlocking loops of thread. 

noun
  • A certain crest of enamel on the molar teeth of some rhinoceroses. 

  • Needlework made by looping thread with a hooked needle. 

pin down

verb
  • To attach or secure with pins. 

  • To hold the opponent back-first so both his or her shoulders touch the mat or ground. 

  • To identify something (e.g. a decision or plan) clearly or specifically. 

  • To corner somebody in order to get a firm answer. 

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