defunct vs erstwhile

defunct

adj
  • No longer in business or service, nor expected to be again. 

  • No longer in use or active, nor expected to be again. 

  • Specifically, of a process: having terminated but not having been reaped (by its parent or an inheritor), and thus still occupying a process slot. See also zombie, zombie process. 

  • (of a language) No longer spoken. 

verb
  • To make defunct. 

noun
  • The dead person (referred to). 

erstwhile

adj
  • Former, previous. 

  • Respected, honourable. 

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