A system of parts that operate or interact like those of a machine: the mechanism of the solar system.
An instrument or a process, physical or mental, by which something is done or comes into being: "The mechanism of oral learning is largely that of continuous repetition” ( T.G.E. Powell).
A habitual manner of acting to achieve an end.
Biology The involuntary and consistent response of an organism to a given stimulus.
Psychology A usually unconscious mental and emotional pattern that shapes behavior in a given situation or environment: a defense mechanism.
The sequence of steps in a chemical reaction.
Philosophy The doctrine that all natural phenomena are explicable by material causes and mechanical principles.