overspeed1
/ˌəʊvəˈspiːd/noun
Excessive speed; especially the operation of an engine, vehicle, etc., at a speed higher than is safe or appropriate; an instance of this.
Origin
Early 19th century; earliest use found in Samuel Singer (1783–1858), literary scholar. From over- + speed.
overspeed2
/ˌəʊvəˈspiːd/verb
1 [no object] To travel too quickly, especially to travel faster than permitted by law or by another authority. Also with object: to cause (a vehicle) to travel more quickly than is safe. Now chiefly in African and S. Asian use.
2 [with object] Chiefly Mechanics. To operate (an engine or other machine) at a speed higher than is safe for its gearing or other components.
Origin
Late 17th century; earliest use found in John Evelyn (1620–1706), diarist and writer. From over- + speed.