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

The batteries will have about as much capacity as 200 Tesla Model 3s, and a 500-mile range without using the diesel engine.

From The Wall Street Journal • Jan. 15, 2026

"I feel like I'm more of a diesel engine sometimes where I need to get going first, then at some point I'll start playing good tennis. I have to play a preparation tournament."

From Barron's • Jan. 3, 2026

The main propulsion diesel engine shut down after the pumps lost electrical power.

From Seattle Times • May 14, 2024

The powerful diesel engine roars as the water taxi cuts through the choppy water that connects Rotterdam's gritty port areas to what remains of the city's historic maritime grandeur.

From BBC • Dec. 17, 2023

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

From "The Road" by Cormac McCarthy

Related Words

• diesel