noun

1. the working parts or arrangement of parts of a machine; works the mechanism of a clock
2. 1. a system whose parts work together like those of a machine the mechanism of the universe
   2. any system or means for doing something; esp., a physical or mental process or processes, whether conscious or unconscious, by which some result is produced; machinery
3. the mechanical aspect; technical part
4. the theory or doctrine that all the phenomena of the universe, particularly life, can ultimately be explained in terms of matter moving in accordance with the laws of nature

Etymology: ModL mechanismus < Gr mēchanē, machine