Dictionaries give two broad definitions of the term shock absorber; as 'a device for absorbing the energy of sudden impulses or shocks in machinery or structures' or as 'a device on a vehicle, especially a car or an aircraft, which reduces the effects of travelling over rough ground or helps it to land more smoothly.'

A shock absorber is a mechanical support designed to smooth out a sudden shock impulse and dissipate kinetic energy over an extended period of time. There are several commonly-used approaches to shock absorption:

Pneumatic and hydraulic shock absorbers commonly take the form of a cylinder with a sliding piston inside. Spring-based shock absorbers commonly use helical springs or leaf springs, though coil springs can be used to absorb torsional shocks as well.

Shock absorbers are an important part of automobile suspensions, aircraft landing gear, and the supports for many industrial machines. Large shock absorbers have also been used in architecture to reduce the susceptibility of structures to earthquake damage.