Boingboing picked up a post from the Oxford University Press that details "nine words you might think came from science but which are really from science fiction." My favorite's "zero gravity."
"Zero-gravity/zero-g. A defining feature of life in outer space (sans artificial gravity, of course). The first known use of “zero-gravity” is from Jack Binder (better known for his work as an artist) in 1938, and actually refers to the gravityless state of the center of the Earth’s core. Arthur C. Clarke gave us “zero-g” in his 1952 novel Islands in the Sky."