erstwhile vs future

erstwhile

adj
  • Former, previous. 

  • Respected, honourable. 

future

adj
  • Having to do with or occurring in the future. 

noun
  • An object that retrieves the value of a promise. 

  • A minor-league prospect. 

  • The time ahead; those moments yet to be experienced. 

  • The likely prospects for or fate of someone or something in time to come. 

  • Something that will happen in moments yet to come. 

  • Verb tense used to talk about events that will happen in the future; future tense. 

  • Goodness in what is yet to come. Something to look forward to. 

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