steam engine

American  

noun

1. an engine worked by steam, typically one in which a sliding piston in a cylinder is moved by the expansive action of the steam generated in a boiler.

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steam-engine British  

noun

1. an engine that uses the thermal energy of steam to produce mechanical work, esp one in which steam from a boiler is expanded in a cylinder to drive a reciprocating piston

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steam engine Scientific  

1. An engine in which the energy of hot steam is converted into mechanical power, especially an engine in which the force of expanding steam is used to drive one or more pistons. The source of the steam is typically external to the part of the machine that converts the steam energy into mechanical energy.

2. Compare internal-combustion engine

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Other Word Forms

• steam-engine adjective

Etymology

Origin of steam engine

First recorded in 1745–55

Example Sentences

The first venture capitalists were wealthy individuals like Brown and Englishman Matthew Boulton—who subsidized James Watt’s steam engine in Great Britain—and scions of wealthy dynasties like the Rockefellers in the U.S.

From Barron's • Jan. 28, 2026

It sat next to a steam engine dubbed “Old Dinah” that eventually replaced the mule teams.

From Los Angeles Times • May 15, 2024

Keeping up with the pace of technology has challenged Congress since the steam engine and the cotton gin transformed the nation’s industrial and agricultural sectors.

From Seattle Times • Apr. 10, 2024

Horses gave way to the steam engine, then the internal combustion engine, then the jet engine.

From BBC • Dec. 9, 2023

Still, when the train came into view, steam engine hissing, pistons hammering, Fannie picked up her skirts and ran alongside the train cars, shouting at the men inside.

From "Fannie Never Flinched" by Mary Cronk Farrell