Robot
The Encyclopedia Galactica defines a robot as a mechanical apparatus designed to do the work of a man. The marketing division of the Sirius Cybernetics Corporation defines a robot as "Your Plastic Pal Who's Fun to Be With."
The Hitchhiker's Guide to the Galaxy defines the marketing division of the Sirius Cybernetics Corporation as "a bunch of mindless jerks who'll be the first against the wall when the revolution comes," with a footnote to the effect that the editors would welcome applications from anyone interested in taking over the post of robotics correspondent.
Curiously enough, an edition of the Encyclopedia Galactica that had the good fortune to fall through a time warp from a thousand years in the future defined the marketing division of the Sirius Cybernetics Corporations as "a bunch of mindless jerks who were the first against the wall when the revolution came."