Source : Webster's Revised Unabridged Dictionary (1913)

Motor \Mo"tor\, n. [L., fr. movere, motum, to move.]
   1. One who, or that which, imparts motion; a source of
      mechanical power.

   2. (Mach.) A prime mover; a machine by means of which a
      source of power, as steam, moving water, electricity,
      etc., is made available for doing mechanical work.

Motor \Mo"tor\, Motory \Mo"to*ry\, Motorial \Mo*to"ri*al\, a.
   [L. motorius that has motion. See {Motor}, n.]
   Causing or setting up motion; pertaining to organs of motion;
   -- applied especially in physiology to those nerves or nerve
   fibers which only convey impressions from a nerve center to
   muscles, thereby causing motion.

Motor \Mo"tor\, n.
   A motor car; an automobile. [Colloq.]

Source : WordNet®

motor
     adj 1: conveying information to the muscles from the CNS; "motor
            nerves" [syn: {centrifugal}, {motor(a)}]
     2: causing or able to cause motion; "a motive force"; "motive
        power"; "motor energy" [syn: {motive(a)}]

motor
     v : travel or be transported in a vehicle; "We drove to the
         university every morning"; "They motored to London for
         the theater" [syn: {drive}]

motor
     n 1: machine that converts other forms of energy into mechanical
          energy and so imparts motion
     2: a nonspecific agent that imparts motion; "happiness is the
        aim of all men and the motor of all action"