apply vs retrofit

apply

verb
  • To pertain or be relevant to a specified individual or group. 

  • To make use of, declare, or pronounce, as suitable, fitting, or relative 

  • To address; to refer; generally used reflexively. 

  • To lay or place; to put (one thing to another) 

  • To put closely; to join; to engage and employ diligently, or with attention 

  • To submit oneself as a candidate (with the adposition "to" designating the recipient of the submission, and the adposition "for" designating the position). 

  • To put to use; to use or employ for a particular purpose, or in a particular case 

retrofit

verb
  • 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 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 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. 

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. 

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