flail vs rivet

flail

noun
  • A weapon which has the (usually spherical) striking part attached to the handle with a flexible joint such as a chain. 

  • A tool used for threshing, consisting of a long handle with a shorter stick attached with a short piece of chain, thong or similar material. 

verb
  • To beat using a flail or similar implement. 

  • To wave or swing vigorously 

  • To thresh. 

  • To move like a flail. 

rivet

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

  • Any fixed point or certain basis. 

verb
  • To command the attention of. 

  • To attach or fasten parts by using rivets. 

  • To make firm or immovable. 

  • To install rivets. 

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