|diesel engine or diesel motor|
|a type of internal-combustion engine in which atomized fuel oil is sprayed into the cylinder and ignited by compression alone|
|diesel motor or diesel motor|
|diesel engine (dē'zəl) Pronunciation Key
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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.