science fiction /ˈsaɪəns ˌfɪkʃən/noun 2adjective 1forms 2 noun2 •Fiction in which advanced technology or science is a key element.Science fiction can be defined as that branch of literature which deals with the reaction of human beings to changes in science and technology. — 1975 •Technology that, while theoretically possible, is not yet practical.Despite decades of research, mass-market personal aircraft are still science fiction. adjective1 •Of or pertaining to this genre. formsscience fictions · science-fictions