breastpin vs cotter

breastpin

noun
  • An ornamental pin attached to clothing in a person's upper chest area; a brooch. 

cotter

noun
  • A cotter pin. 

  • A peasant who performed labour in exchange for the right to live in a cottage. 

  • A pin or wedge inserted through a slot to hold machine parts together. 

verb
  • To fasten with a cotter. 

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