Definition
A pre-takeoff ground check in which the pilot holds the airplane stationary with brakes applied and increases engine power to a specified RPM to verify that the engine, magnetos, propeller, carburetor heat, and related systems are operating correctly before flight.
Plain English
A test you do on the ground, before takeoff, where you push the throttle up to a set power setting and check that the engine and its systems are working properly.
Context Anchor
Seen on pre-takeoff checklists and in carburetor heat procedures, usually before entering the runway.
Derivation
The term comes from the act of 'running the engine up' to a higher power setting than idle. 'Runup' simply describes bringing the engine up in RPM to a test power, holding it there, and observing the results.
Why Pilots Care
Reveals engine or ignition problems that could lead to failure after leaving the ground.
Intuition Check
Do not read engine runup as simply warming the engine. In this context, it means a specific pre-takeoff check of engine power and related systems.
Example Sentence 1
During the engine runup, the pilot noticed a larger-than-normal RPM drop on the right magneto and taxied back to investigate.
Example Sentence 2
After completing the engine runup the pilot taxied onto the runway for departure.