Headcanon

[Mark Zuckerberg]

Used by followers of various media of entertainment, such as television shows, movies, books, etc. to note a particular belief which has not been used in the universe of whatever program or story they follow, but seems to make sense to that particular individual, and as such is adopted as a sort of personal canon. Headcanon may be upgraded to canon if it is incorporated into the program or storys universe.

[Hina Muqadas]

(also written as head canon, but its really one word.)

An idea, belief, or aspect of a story that is not mentioned in the media itself, but is accepted by either the media consumer themselves or the [fandom] in general. If it is confirmed by the creator of the story, it becomes [canon].

[Jason Yan]

Headcanons are traits, events and actions a fictional character is give to add more persona. Used by followers of various media of entertainment, such as television shows, movies, books, etc. Headcanons arent specific .They are mostly add-ons to a profile of a character from someones belief, mainly never or possibly hinted by the creator.

[Hina Muqadas]

Definitely in no way related to Hetalia, it refers to what a character from the webcomic Homestuck sounds like in their heads

[Jason Yan]

An [extreme] act of [oral sex] on [a penis].