appurtenance vs retrofit

appurtenance

noun
  • Equipment used for some specific task; gear. 

  • That which appertains; an appendage to something else; an addition. 

  • A subordinate interest in land which benefits a principal estate, which cannot be detached from or held separately to that estate; an appurtenant interest. 

  • A modifier that is appended or prepended to another word to coin a new word that expresses belonging. 

  • The state or quality of being an appurtenance. 

retrofit

noun
  • An act of supplying a device, structure, etc., with new components or parts that were not previously available or installed; a retrofitting. 

  • A change made to a device, structure, etc., by introducing components or parts that were not previously available or installed. 

verb
  • To supply (a device, structure, etc.) with new components or parts that were not previously available or installed; to modernize. 

  • Synonym of backport (“to retroactively supply a fix or feature to a previous version of a software product at the same time or after supplying it to the current version.”) 

  • To give new characteristics or make alterations (to someone or something) to suit them to changed circumstances. 

  • To supply a device, structure, etc., with new components or parts that were not previously available or installed. 

  • To add or substitute (new components or parts) that were not previously available for or installed in a device, structure, etc. 

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