callback vs repercussion

callback

noun
  • The return of a situation to a previous position or state. 

  • A joke which references an earlier joke in the same routine. 

  • A follow-up audition in casting. 

  • A function pointer passed as an argument to another function. 

  • A return telephone or radio call; especially one made automatically to authenticate a logon to a computer network. 

  • A form of audience participation in which the audience shout lines in response to the dialog of a film. 

  • A product recall because of a defect or safety concern. 

repercussion

noun
  • The act of driving back, or the state of being driven back; reflection; reverberation. 

  • In a vaginal examination, the act of imparting through the uterine wall with the finger a shock to the foetus, so that it bounds upward, and falls back again against the examining finger. 

  • The subsidence of a tumour or eruption by the action of a repellent. 

  • A consequence or ensuing result of some action. 

  • Rapid reiteration of the same sound. 

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