a rotary internal-combustion engine having a three-lobed rotor and requiring fewer parts than a comparable piston-operated engine: it is less efficient and less powerful than reciprocating engines
after Felix Wankel (1902-88), Ger engineer and inventor
See Wankel engine in American Heritage Dictionary 4
A rotary internal-combustion engine in which a triangular rotor turning in a specially shaped housing performs the functions allotted to the pistons of a conventional engine, thereby allowing great savings in weight and moving parts.
Origin: After Felix Wankel (1902-1988), German engineer