Plain English Meaning

An engine that makes power by burning fuel inside cylinders to push pistons back and forth, and that motion is turned into spinning motion to drive the propeller. It is the same basic kind of engine found in most cars.

Full Definition

Piston-driven internal combustion engines in which fuel is burned inside cylinders, pushing pistons up and down. This back-and-forth (reciprocating) motion is converted by a crankshaft into the rotational motion that turns the propeller.

Context Anchor

Seen in aircraft systems discussions, especially when describing the engine type used by many small training airplanes.

Derivation

From the Latin reciprocare, meaning to move back and forth. The name describes the piston motion: each piston travels up and down repeatedly inside its , and that back-and-forth movement is what produces .