self-propulsion


self-pro·pelled

(sĕlf′prə-pĕld′)adj.1. Containing its own means of propulsion: a self-propelled golf cart.2. Fired from or mounted on a moving vehicle: a self-propelled howitzer.
self′-pro·pul′sion (-pŭl′shən) n.

self-propulsion

n propulsion of a vehicle through its own source of tractive power rather than by an external means