fastener vs fibula

fastener

noun
  • Mechanically, any device that fastens; especially, a collective term for items such as screws, nuts, washers, clasps, bolts and the like. 

  • Something or someone that fastens. 

fibula

noun
  • An ancient kind of brooch used to hold clothing together, similar in function to the modern safety pin. 

  • The smaller of the two bones in the lower leg. 

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