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.
- A machine or mechanical appliance.
- The arrangement of connected parts in a machine.
- 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.