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.

---

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

---

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.

---

Etymology

Origin of diesel engine

First recorded in 1890–95

Example Sentences

See Examples For:

diesel engine

Later this year, the car will take to the iconic Bonneville Salt Flats in Utah to try to break the current diesel engine record of 350.092 mph - set by JCB in 2006.

From BBC ● Jun. 1, 2026

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

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

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

From "The Road" by Cormac McCarthy

Related Words

• diesel