Headcanon

Part of speech: noun

Definitions

1. An informal personal assumption a fan adopts about a fictional character or world that the official source never actually states
2. A fan's own unofficial backstory or detail for a fictional story, accepted privately rather than drawn from the original canon
3. Unofficial background detail or interpretation that a fan imagines for a character, treated as true only within their own view of the fiction

Etymology: "Headcanon" is a compound of "head" and "canon," and its story is one of the most recent in this kind of wordbook: it was first recorded around 2007. "Canon" comes from Greek "kanōn," a measuring rod or rule, which entered English through Latin and Old English and came to mean an authoritative body of works or doctrines. "Head" is the ordinary English word for the mind or imagination, so a headcanon is a canon that exists only in the reader's or fan's head. The idea behind it is simple. A fan may decide, privately, that a fictional character has a certain background, habit, or relationship that the original work never states. Those details are not official, yet they shape how the fan reads the story. The compound thus pairs the strict, rule-giving sense of "canon" with a personal, unofficial one.

Synonyms: fan theory, fanon