This is the first historical dictionary devoted to science fiction. It shows the development of science-fiction words and their associated concepts over time, with full citations and bibliographic information. Citations are drawn from science-fiction books and magazines, fanzines, screenplays, newspapers, comics, folk songs, and the Internet. The dictionary reveals how many words we consider to be everyday expressions, like ‘space shuttle’, ‘blast off’, and ‘robot‘, have their roots in imaginative literature and not in hard science. It also charts the transfer of science-fiction vocabulary to different subcultures and endeavours, such as neo-paganism, aerospace, computers, and environmentalism.