diesel engine

American  

noun

1. a compression-ignition engine in which a spray of fuel, introduced into air compressed to a temperature of approximately 1000° F (538° C), ignites at a virtually constant pressure.

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diesel engine British  

noun

1. a type of internal-combustion engine in which atomized fuel oil is sprayed into the cylinder and ignited by compression alone

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diesel engine Scientific  

/ dē′zəl /

1. An internal-combustion engine in which the fuel oil is ignited by the heat of air that has been highly compressed in the cylinder, rather than by a spark. Due to the need for the engine to withstand very high pressures, diesel engines are relatively heavy; however, they are relatively fuel-efficient, especially when running at low power.

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Etymology

Origin of diesel engine

First recorded in 1890–95

Example Sentences

Higher demand for cleaner diesel engine technology amid ever-tightening regulatory standards is part of the story.

From Barron's • May 21, 2026

Unlike a traditional gasoline or diesel engine, it has no pistons.

From The Wall Street Journal • Apr. 24, 2026

The shift to EVs could have consequences for the close-to 1,800 staff at the Ford diesel engine plant in Dagenham, which was the largest car factory in Europe when it was first built.

From BBC • Nov. 19, 2025

The Dali’s diesel engine automatically shut down because its cooling pumps lost power.

From Seattle Times • May 15, 2024

They could hear the diesel engine out on the road, running on God knows what.

From "The Road" by Cormac McCarthy

Related Words

• diesel