extra vs retrofit

extra

noun
  • Something additional, such as an item above and beyond the ordinary school curriculum, or added to the usual charge on a bill. 

  • A run scored without the ball having hit the striker's bat - a wide, bye, leg bye or no ball. 

  • A supernumerary or walk-on in a film or play. 

  • An extra edition of a newspaper, which is printed outside of the normal printing cycle, for example to report an important late-breaking event. 

  • The state or trait of being over the top, of behaving in an overly dramatic manner. 

  • Something of an extra quality or grade. 

adj
  • Beyond what is due, usual, expected, or necessary; extraneous; additional; supernumerary. 

  • Over the top; going beyond what is normal or appropriate, often in a dramatic manner. 

adv
  • To an extraordinary degree. 

det
  • Denotes more. 

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 extra and retrofit occurred in a corpus of books? (source: Google Ngram Viewer )