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

LiquidPiston’s engine can run on everything from diesel to jet fuel, while being a fraction of the size of a comparable diesel engine, and up to 30% more efficient than a comparable gasoline one.

From The Wall Street Journal • Apr. 24, 2026

On top of the five-year diesel engine import ban, Hino has also committed to a compliance and ethics plan during that period.

From BBC • Jan. 16, 2025

The train ride — a one-eighth scale model of a diesel engine — first arrived at Descanso Gardens as a seasonal attraction in the 1980s, and became a permanent feature in 1996.

From Los Angeles Times • Jul. 18, 2024

The truck driver slammed the door and started the diesel engine.

From "Ceremony:" by Leslie Marmon Silko

Related Words

• diesel