Plain English Meaning
A propeller placed behind the engine that pushes the aircraft forward, instead of being on the nose pulling it forward like most light aircraft.
Full Definition
A propeller mounted at the rear of the engine (or aircraft) so that it pushes the aircraft forward through the air, rather than pulling it. The propeller faces aft, and thrust is generated behind the engine instead of in front of it.
Context Anchor
Seen in aircraft design descriptions, preflight discussions, and ramp safety around aircraft with rear-mounted propellers.
Derivation
Called a 'pusher' because it pushes the aircraft from behind. The opposite arrangement, where the propeller is on the nose and pulls the aircraft forward, is called a 'tractor' propeller (from Latin trahere, 'to pull').
Why Pilots Care
Changes center-of-gravity considerations, forward , and propeller-strike risks on the .