Definition of "Mechanism" :

noun: the technical aspects of doing something

"A mechanism of social control."

noun: device consisting of a piece of machinery; has moving parts that perform some function

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

noun: a natural object resembling a machine in structure or function

"The mechanism of the ear."

noun: the atomic process that occurs during a chemical reaction

"He determined unique mechanisms for the photochemical reactions."