rivet vs untie

rivet

verb
  • To command the attention of. 

  • To attach or fasten parts by using rivets. 

  • To make firm or immovable. 

  • To install rivets. 

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. 

untie

verb
  • In the Perl programming language, to undo the process of tying, so that a variable uses default instead of custom functionality. 

  • To resolve; to unfold; to clear. 

  • To become untied or loosed. 

  • To loosen, as something interlaced or knotted; to disengage the parts of. 

  • To free from fastening or from restraint; to let loose; to unbind. 

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