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

Once they arrived, inventions like the steam engine and indoor plumbing likely helped the insects travel further and get cozy living indoors, where they are most commonly found today.

From Seattle Times • May 20, 2024

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

From Los Angeles Times • May 15, 2024

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

From BBC • Dec. 9, 2023

He followed her, staggered a little on landing, then straightened up in time to see the gleaming scarlet steam engine pick up speed, round the corner, and disappear from view.

From "Harry Potter and the Half-Blood Prince" by J.K. Rowling