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

Thanks to some daring industrial espionage, the steam engine finally got into American hands, and offered investors opportunities in mills, foundries, canals, and especially railroads.

From Barron's • Jan. 13, 2026

The turkey drives to the capital ended when the steam engine and railways came along in the late 1800s.

From BBC • Dec. 24, 2025

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

In some cases this is obvious: a kite won’t help me understand how a bird flies, or a steam engine how a muscle works.

From "The Invention of Science" by David Wootton