Source : WordNet®

self-propelling
     adj 1: containing within itself the means of propulsion or
            movement; "a self-propelled vehicle" [syn: {automotive},
             {self-propelled}]
     2: moved forward by its own force or momentum; "a
        self-propelled egotist"; "the arms program is now
        self-propelled" [syn: {self-propelled}]