noun
Etymology: translation of Medieval Latin primus motor
1. in some philosophies
a. : the self-moved being to which all motion must ultimately go back
b. capitalized P&M : god — compare first cause
2.
a.
(1) : an initial source of motive power (as an engine) designed to receive and modify force and motion as supplied by some natural source and apply them to drive other machinery (as a waterwheel, turbine, or steam engine)
(2) : a powerful tractor or truck usually with all-wheel drive for hauling artillery or moving stalled vehicles
b. : the original or most effective force in an undertaking or work
see the prime mover of our increased growth in physical environment — Lawrence Farmer
he was a prime mover in the evolution of progressive ensemble jazz — Bill Simon
3. : agonist
Synonyms: see origin