Proper noun
(fandom slang) The unnamed interconnected fictional universe setting of many of the works of Japanese mangaka comic book artist Leiji Matsumoto
(fandom slang, by extension) All the licensed media connected to this setting as well.
(fandom slang) The works of Leiji Matsumoto (松本零士, Matsumoto Reiji) collectively.
(fandom slang, by extension) All the licensed media connected to and deriving from these works as well.