We don't have synonyms for fanboi yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are fanboy.
(n) :
(informal) Alternative spelling of fanboy. [(fandom slang, often derogatory) A male fan who is obsessive about a particular subject (especially, something or someone in popular entertainment media).]
(n) :
(informal) Alternative spelling of fanboy. [(fandom slang, often derogatory) A male fan who is obsessive about a particular subject (especially, something or someone in popular entertainment media).]