A general term that describes all fans and their activities (fanfic, fanart, etc.) for a specific entity, such as the AFI fandom, Star Wars fandom, Harry Potter fandom, etc.

A general term to describe the followers of a particular show.

generic term for fan activities related to a particular show/series/movie/etc. For example, you might hear someone say, "X-Files is my main fandom, but I'm also into Highlander." This is not the same as saying "I watch X-Files and Highlander." The term "fandom" specifically refers to involvement in fan activities such as reading and writing fanfic, going to conventions, posting on show-related lists and websites and message boards, and so forth. The term "genre" is also sometimes used in this context.

(1) The sf subculture. Those involved in producing fanzines, going to cons, etc. (2) Any similar subculture (e.g., comics fandom).

Fandom (from the noun fan and the affix -dom, as in kingdom, dukedom, etc.) is a subculture composed by like-minded fans (aficionados) characterized by a feeling of closeness to others who share the same interest (Thorne&Bruner 2006). Such a community of keen aficionados can share a common interest in a wide selection of phenomena, such as authors, hobbies, genres or fashions. Fandom as a term can also be used to refer to the single interconnected social network of these individual fandoms, many of which overlap.

the community of fans (as in fandom v. mundanes), or a particular universe and its fans (as in S&H fandom v. other fandoms)

the community built around the show.

The community of people who share an interest in the Whedonverse (or other shows), includes Live Journal communities, email lists, discussion boards, those who get together for conferences, etc.

karass of fans. fans all have an abiding interest in whatever it is that they're fans of.

Science fiction fandom. Science Fiction fandom considers itself so all encompassing that it drops the "SF" when referring to itself.

Term used to encompass all fans of a particular show.

Unless qualified or used in a specific context, refers to sci-fi and fantasy (“SF/F”) fandom — particularly as an (at least somewhat) organized phenomenon.

(n.) A term for Special Interest Groups (SIGs) that describes the members of that group.

the fans of a sport or famous person

the original source of the characters/setting.