Definition of overspeed:
(v) :
(intransitive) To travel excessively fast or beyond the permitted rate.
(v) :
(India, intransitive) To speed; to drive a vehicle faster than the permitted speed limit.
(v) :
(usually transitive, sometimes intransitive, chiefly mechanics) To operate an engine or machine too fast.
(n) :
Speed that exceeds a reasonable or permitted rate.