Definition

The officially accepted body of works, storylines, or established facts within a fictional universe or religious tradition; also refers to the set of principles or rules by which something is judged or understood. In literature and fandom, canon is distinguished from fan-created or unofficial content.

Example Usage

The comic book storyline is no longer considered canon after the studio rebooted the franchise.

Origin

From Greek 'kanon' (measuring rod, rule); used in religious contexts since early Christianity to denote authentic scripture.

Fun Fact

Fandom communities spend considerable time debating what is and isn't canon, especially when sequels, spin-offs, or adaptations contradict previous works.

Source: Definition backfill (hailey)