Definition of mechanism
1a
: a piece of machinery (see machinery sense 1)
The camera's shutter mechanism is broken.
b
: a process, technique, or system for achieving a result
the mechanisms of peace— F. D. Roosevelt
2
: mechanical operation or action : working sense 2
he acknowledges nothing besides matter and motion; so that all must be performed either by mechanism or by accident— Richard Bentley
3
: a doctrine that holds natural processes (as of life) to be mechanically determined and capable of complete explanation by the laws of physics and chemistry
4
: the fundamental processes involved in or responsible for an action, reaction, or other natural phenomenon
meteorologists believe that this pressure jump is the mechanism responsible for storms and tornadoes — Think
— compare defense mechanism
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Merriam-Webster unabridged
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Time Traveler for mechanism
The first known use of mechanism was in 1662
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