means A machine that converts energy — usually electrical or chemical — into mechanical motion, the thing that makes a fan spin, a car go, or a pump push.

from From Latin 'motor,' meaning 'mover,' from 'movere,' 'to move' — the same root that gives us 'motion,' 'momentum,' and 'emotion.' For centuries it simply meant 'one who moves something,' but in the 19th century, as engines and electric drives came of age, 'motor' was handed its modern job: the device that does the moving, no longer the person.