rocket engine

American  

noun

1. a reaction engine that produces a thrust due to an exhaust consisting entirely of material, as oxidizer, fuel, and inert matter, that has been carried with the engine in the vehicle it propels, none of the propellant being derived from the medium through which the vehicle moves.

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rocket engine British  

noun

1. Also called: rocket motor.  a reaction engine in which a fuel and oxidizer are burnt in a combustion chamber, the products of combustion expanding through a nozzle and producing thrust

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rocket engine Scientific  

1. An engine used to produce a jet of hot gases to propel a rocket. The jet is produced by combustion of a fuel with other chemicals stored in the rocket. Since they do not rely on the oxygen in the atmosphere for combustion, rocket engines can operate in space.

2. Compare turbojet

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Etymology

Origin of rocket engine

First recorded in 1930–35

Example Sentences

"This large rocket engine will slow down the ISS, and enable it to have a precise re-entry over the Pacific Ocean, far from land, people or any other potential hazards," Horack explained.

From Barron's • Feb. 5, 2026

Arbor’s solution is more like a tree-powered rocket engine.

From Los Angeles Times • Sep. 30, 2025

A rocket engine has exploded during a launch test at the UK's new spaceport in Shetland.

From BBC • Aug. 19, 2024

During a test of a Harpoon anti-ship missile, its booster — the rocket engine that launches the missile — was “activated” but not ignited, and then it could not be deactivated, the Danish military said.

From New York Times • Apr. 4, 2024

An Agena is a slim fuel tank about thirty feet long, with a rocket engine sticking out of one end and a hole in the opposite end.

From "Flying to the Moon: An Astronaut's Story" by Michael Collins