autŏmătus

I. self - moving, voluntary, spontaneous: plausus, Petr. 50, 1.—Hence, subst.: autŏmătŏn or -um, n, a self-moving machine, an automaton, Vitr. 9, 9; Petr. 54, 4; 140, 10; * Suet. Claud. 34 fin.