retcon

/ˈɹɛtˌkɒn/

IPA: /R EH1 T K AA0 N/

noun
  1. 1

    A situation, in a soap opera or similar serial fiction, in which a new storyline explains or changes a previous event or attaches a new significance to it.

verb
  1. 1

    To employ such a device.

Source: https://en.wiktionary.org/wiki/retcon