Image via WikipediaMundane (n.) - A slang term from science fiction fandom which describes all non-fans. In many instances the term is used as a perjorative. Mundanes is also a term adopted for similar usage by other related subcultures, including goths, who use it to describe non-goths, and the Society for Creative Anachronists, who use it describe anyone who isn't a participating member of the SCA.
The term mundane, sometimes shortened as mun or mundie, is also used within works of science fiction and fantasy. For example, telepaths in the Babylon 5 universe refer to all non-telepaths as mundanes and in the Fables graphic novel series, all characters that do not orginate from fairy tales or folklore are referred to as mundies.
Moreover, there is a subgenre of science fiction known as mundane sci-fi, which adheres to highly realistic and plausible settings and plot devices within its stories, eschewing the more fantastical and extraordinary tropes more often associated with mainstream science fiction, particularly space opera.
Thus, usage of mundane within fandom is somewhat recursive, referring at various times to characters, stories, non-fans, or as a derogatory term for fans that are perceived as inferior or lacking sufficient devotion to fandom in general or an individual franchise in particular. Mundane as a fandom descriptor has fallen somewhat out of usage in recent years in favor of the Harry Potter-inspired (and thus currently more widely recognized) term muggle.
I bring it up because: Today is the first day of the 2009 World Science Fiction Convention, whence come the Hugo Awards, and if any place is likely to illustrate the varied usage of the word mundanes (to say nothing of the obvious dichotomy between fandom and the mundanes) it's WorldCon. Moreover, today is the 75th birthday of author Piers Anthony, whose obscenely long Xanth series of fantasy novels includes one of the most popular invocations of the term mundane, which in his context describes any normal human not born of the fictional world of Xanth. We commend either occasion as an excuse to reach out to any of the Mundanes in your life and share a little bit of the joy of fandom with them. Or just point and call them a mundie. Whatever leads to joy, really.