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mechanism

MEK-uh-niz-um /ˈmɛkənɪzəm/

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GeneralTechnicalAcademic

A system of parts working together in a machine; a piece of machinery.

While 'machine' refers to the entire device, 'mechanism' refers to the specific internal assembly of moving parts that performs a distinct mechanical function. For example, a clock is a machine, but the escapement that keeps time is a mechanism.

The story behind the word. The word mechanism traces back to the ancient Greek 'mekhane', which referred to any tool, machine, or clever device (including the cranes used in Greek theater to lower actors playing gods onto the stage). It entered English via Latin and French, evolving to describe the internal, clockwork-like workings of physical systems.

Word relationships

device: A device is a broad term for any physical object made for a purpose, whereas a mechanism specifically implies an assembly of moving, interacting mechanical parts.

structure: A structure is a static assembly of parts designed to support loads without moving, whereas a mechanism is designed specifically to move.

Commonly confused with

machine: A machine is a complete system that performs work (often including a power source), while a mechanism is the specific kinematic assembly of parts within that machine.

Word family

mechanize (verb): To equip with machinery or make mechanical.
mechanical (adjective): Relating to machinery or tools.
mechanic (noun): A person who repairs or maintains machinery.

Collocations

locking mechanism
trigger mechanism
steering mechanism
escapement mechanism

Example sentences

"The locking mechanism of the safe consists of several interlocking brass tumblers that must align perfectly." A description of a high-security lock
"The Antikythera mechanism, discovered in an ancient shipwreck, is considered the world's oldest analog computer." An article about historical inventions (The Antikythera Mechanism: Research and Publication Project)
"We must simplify the folding mechanism of the solar panels to ensure they deploy reliably in space." An engineering lecture on design

Memory hook

Think of a 'mechanic' working on a complex 'mechanism' inside a car engine. A mechanism is the inner workings of a machine.

When not to use

Avoid using 'mechanism' when referring to a single, static structural component like a beam or a bracket.

Fun facts

The term 'deus ex machina' (god from the machine) refers to the theatrical mechanism used in ancient Greece to lift actors playing gods.
In chemistry, a 'reaction mechanism' describes the step-by-step sequence of elementary reactions by which overall chemical change occurs, borrowing the mechanical metaphor of a clockwork process.

Related words

linkage, gear, transmission

Explore more words

mechanistic, Component, apparatus, mechanize, assembly, differential