rivet vs unfasten

rivet

noun
  • Any fixed point or certain basis. 

  • A cylindrical mechanical fastener that attaches multiple parts together by fitting through a hole and deforming the head(s) at either end. 

verb
  • To command the attention of. 

  • To attach or fasten parts by using rivets. 

  • To make firm or immovable. 

  • To install rivets. 

unfasten

verb
  • To come unloosed or untied. 

  • To detach from any connecting agency or link; to disconnect. 

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