In the energy industry, this term refers to a device, substance or process that provides the kinetic energy to move a machine, in this case an electrical generator. In some circles, the latin primium mobile is used in place of prime mover. The term most commonly refers to a device, so turbines are often referred to as prime movers, but it may be more accurate to refer to the fuel that powers the turbine (or the fuel that creates the steam which powers a non-combustion turbine) as the prime mover.

Prime mover has acquired several colloquial meanings in recent years which relate to varying degrees to the term's original meaning. A pop song, book or movie rising rapidly up the popularity or sales charts is referred to as a prime mover, as is a politician who is rapidly gaining power and influence. A market force or condition which currently acts as a major contributor to a market's growth is a prime mover of the market, and an attractive or charismatic individual is considered a prime mover in social or business circles.

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