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

Yet that is an odd complaint for Washington to make, since at the WTO’s creation, in 1995, the United States was the prime mover behind the dispute settlement system and insisted on stronger rules and tougher enforcement mechanisms than in the previous General Agreement on Tariffs and Trade. —Douglas A. Irwin, Foreign Affairs, 6 Nov. 2018

The prime mover within the organization — the largest user — was the U.S. signatory, the Communications Satellite Corporation, or Comsat. —Neal B. Freeman, National Review, 17 Sep. 2024

Some faculty brought up the spectre of student evaluations, which has been cited as a prime mover behind grade inflation and can also factor into decisions about tenure and contract renewals. —Jessica Winter, The New Yorker, 3 Sep. 2024

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