Mechanism

The arrangement or relation of the parts of a machine; the parts of a machine, taken collectively; the arrangement or relation of the parts of anything as adapted to produce an effect; as, the mechanism of a watch; the mechanism of a sewing machine; the mechanism of a seed pod.

Mechanical operation or action.

An ideal machine; a combination of movable bodies constituting a machine, but considered only with regard to relative movements.

the atomic process that occurs during a chemical reaction; "he determined unique mechanisms for the photochemical reactions"

(philosophy) the philosophical theory that all phenomena can be explained in terms of physical or biological causes

the technical aspects of doing something; "a mechanism of social control"; "mechanisms of communication"; "the mechanics of prose style"