mechanism

UK: /ˈmɛkənɪzəm/ US: /ˈmɛkəˌnɪzəm/ ,(mek′ə niz′əm)

WordReference Random House Learner's Dictionary of American English © 2025

mech•an•ism /ˈmɛkəˌnɪzəm/   n. [countable]

1. Mechanical Engineering an assembly of moving parts performing a function:
   The alarm mechanism is jammed.
2. the way or means by which an effect is produced:
   the language learning mechanism in the human brain.
3. a procedure within an organization:
   What is the mechanism for adjusting the bylaws?
4. Psychiatry a manner of behaving that helps one deal with the environment:
   His amnesia was a defense mechanism.

See -mech-.

WordReference Random House Unabridged Dictionary of American English © 2025

mech•an•ism  (mek′ə niz′əm), n. 

1. Mechanical Engineering an assembly of moving parts performing a complete functional motion, often being part of a large machine;
   linkage.
2. the agency or means by which an effect is produced or a purpose is accomplished.
3. Mechanical Engineering machinery or mechanical appliances in general.
4. Mechanical Engineering the structure or arrangement of parts of a machine or similar device, or of anything analogous.
5. Mechanical Engineering the mechanical part of something;
   any mechanical device:
   the mechanism of a clock.
6. routine methods or procedures;
   mechanics:
   the mechanism of government.
7. mechanical execution, as in painting or music;
   technique.
8. Philosophy the theory that everything in the universe is produced by matter in motion;
   materialism. Cf. dynamism (def. 1), vitalism (def. 1).
9. Philosophy
   • the view that all natural processes are explicable in terms of Newtonian mechanics.
   • the view that all biological processes may be described in physicochemical terms.
10. Psychiatry the habitual operation and interaction of psychological forces within an individual that assist in interpreting or dealing with the physical or psychological environment.

• Greek mēchan(é̄) machine + Neo-Latin -ismus, Late Latin -isma -ism
• Neo-Latin mēchanismus; Late Latin mēchanisma a contrivance
• 1655–65

mech′a•nis′mic, adj. 

Collins Concise English Dictionary © HarperCollins Publishers::

mechanism / ˈmɛkəˌnɪzəm/ noun

1. a system or structure of moving parts that performs some function, esp in a machine
2. something resembling a machine in the arrangement and working of its parts
3. any form of mechanical device or any part of such a device
4. a process or technique, esp of execution: the mechanism of novel writing
5. the doctrine that human action can be explained in purely physical terms, whether mechanical or biological
6. strict determinism
   Compare dynamism, vitalism
7. the ways in which psychological forces interact and operate
8. a structure having an influence on the behaviour of a person, such as a defence mechanism