Self-acting
Pronunciation : Self`-act"ing
Part of Speech : a.
Definition : Defn: Acting of or by one's self or by itself; -- said especially of a machine or mechanism which is made to perform of or for itself what is usually done by human agency; automatic; as, a self-acting feed apparatus; a self-acting mule; a self-acting press.
Source : Webster's Unabridged Dictionary, 1913