Definition from Wiktionary, the free dictionary
fanboy (plural fanboys)
- (fandom slang) A (usually, male) fan who is obsessive about a particular subject (especially, something or someone in popular entertainment media).
1988 August, Bart Bull, “Comics”, Spin, volume 4, number 5, ISSN 0886-3032, page 41:
- (It's in the nature of comic book fanboy obsessiveness that all of these Eras and Ages and such have been religiously chronicled; it's equally in their nature that no two fanboys can ever agree about anything about any of these Ages and Eras; everything is up for debate, eternally and in microscopic detail.)
1998 September, Brian Doherty, “Exposure: Tales From the Dark Side”, Spin, volume 14, number 9, ISSN 0886-3032, page 108:
- Six years and seven titles later, their company, Top Cow, is the third-biggest-grossing comic line, thanks mainly to a pair of blood-soaked, modern-day Gothics that hare been a hit both with fanboys and a growing number of women.
someone devoted to a single subject