- 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.
Meaning of 'self-acting' (Princeton's WordNet)
1 . self-acting
[ s]
Meaning (1): - designed to activate or move or regulate itself