prime mover

noun

1

a

: an initial source of motive power (such as a windmill, waterwheel, turbine, or internal combustion engine) designed to receive and modify force and motion as supplied by some natural source and apply them to drive machinery

b

: a powerful tractor or truck usually with all-wheel drive

2

: the self-moved being that is the source of all motion

3

: the original or most effective force in an undertaking or work

education is … a prime mover of cultural and societal change

—R. C. Buck

Examples of prime mover in a Sentence

She was the prime mover behind the town's annual summer festival.

Recent Examples on the Web

The prime movers behind the daylong festivals are Lesh’s sons, Grahame, 37, and Brian, 34. —Paul Liberatore, The Mercury News, 21 June 2024

Banks, who abruptly resigned as NYPD Chief of Department in 2014 amid a federal corruption investigation in which he was never charged, also acted as a prime mover in the latest attempt to unseat Rice as chairwoman, the sources said. —Graham Rayman, New York Daily News, 24 Apr. 2024

In this instance, force in the form of Israeli blood spilled was the prime mover behind Israeli concessions, but U.S. support and new inducements for Israel to withdraw from Gaza played a role as well. —Michael J. Koplow, Foreign Affairs, 31 May 2017

With Callwood as chair and prime mover, We Cancerve took root and grew. —Jonathan M. Pitts, Baltimore Sun, 31 Mar. 2024

Word History

Etymology

(sense 2) translation of Medieval Latin prīmum mōbile, prīmus mōtus, prīmus mōtor or other variants

Note: See also etymology at primum mobile.

First Known Use

1795, in the meaning defined at sense 1a

Medical Definition

prime mover

noun

ˈprīm-ˈmü-vər 

: agonist sense 1