crochet vs safety pin

crochet

noun
  • Needlework made by looping thread with a hooked needle. 

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

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

safety pin

noun
  • A pin in the form of a clasp, which has a guard to cover the sharp point; used to join two pieces of fabric, etc., together temporarily. 

  • The pin of a hand grenade, which prevents accidental detonation. 

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