Definition from Wiktionary, the free dictionary
Etymology 1 
- IPA: /ˈfænən/
fanon (plural fanons)
- A vestment reserved only for the Pope for use during a pontifical Mass.
- Part of a bishop's mitre. They are the tabs extending down from the mitre, often with a cross near the end of each. See lappet.
- A maniple.
Etymology 2 
- (informal, fandom slang) Elements introduced by fans which are not in the official canon of a fictional world but are widely believed to be or treated as if canonical.
- Papal Fanon on Wikipedia.Wikipedia:Papal Fanon
- Fanon in fiction on Wikipedia.Wikipedia:Fanon_(fiction)#Fanon
- Fanon article at TV Tropes
- OED 2nd edition 1989
fanon f (plural fanons)