retcon

noun

1. A fictional setting in which a new storyline explains or changes a previous event or attaches a new significance to it.

   “TLC: What do you say to the Legion fans who have become disenfranchised with the series due to its various retcons and reboots?”

   “Fans talk of retcon—retroactive continuity—giving information that explains an earlier event, especially seeming plot contradictions or lacunae.”

   “It's a little trick called retcon, short for "retroactive continuity," […] Yet I'm unsure even Millar is fully aware of the power given him by the retcon.”

verb

1. To employ such a device.

   “While ‘retconning' the scripts, I came up with a number of theories that throw new light on the Doctor, his past, and various other elements[…]”

   “A lot of people were like, "Oh, they just retconned their own continuity. They should have used Kyle. I don't like that." So we just threw Kyle in there to say, "No, no, Kyle's still there. He still exists in the animated universe; he's just not stationed on Earth at the moment, regularly."”

   “Retroactive continuity (aka retconning), would reveal that Quicksilver and Scarlet Witch are also Magneto's children, showing that this was a guy who was really committed to his cause”

   “Luthor appeared a handful of times, Gary "retconned" the Toyman and created Terra-Man, and Superman would get a worthy opponent whenever Len Wein did a fill-in.”

   “There’s a note of wistful, wishful thinking in all this retconning of reality — would that we could write a time jump into our own scripts!”