= automatic, adj. (in various senses). Now rare.

Of action, etc.: self-generated, spontaneous; (of a thing) self-acting; having the power of motion within itself. In later use (Physiology): having…

That is an automaton; self-acting once set in motion, automatic. Now rare.

That works by itself; = automatic, adj. 1.

Of or relating to (the making of) automatons.

Automatic, automated; like an automaton.

Designating a mechanism or device capable of operating by itself under fixed conditions, with little or no direct human control; (hence also)…

Not controlled by an external agent; autonomous; spec. (of a person or group) self-governed, self-ruled; (of a thing) self-operating…

= automatic, adj. (in various senses).

Automatic.

Of a device, vehicle, weapon, etc.: that operates, directs, or steers itself automatically.

Of a machine, device, etc.: that moves or operates automatically; = automatic, adj. 2b.