(Did you mean the Rob Holdstock fanzine?)
The larger universe — in fan terms, the larger (mundane) world, of which fandom is but a small part, vs. the Microcosm, which is fandom. It's also used simply as a synonym for mundania. These days, however, the Microcosm may be larger than the Macrocosm, if you count all the people yakking about sf and assorted fringe fandoms on the Internet.
|This is a fanspeak page. Please extend it by adding information about when and by whom it was coined, whether its still in use, etc.