Webster's Revised Unabridged Dictionary · 1913

Diesel

Diesel (dē"zel)

[After Dr. Rudolf Diesel, of Munich, the inventor.]

A type of internal-combustion engine in which the air drawn in by the suction stroke is so highly compressed that the heat generated ignites the fuel (usually a heavy oil), the fuel being automatically sprayed into the cylinder under pressure. The Diesel engine has a very high thermal efficiency.

Also: Diesel motor, Diesel engine