Plain English Meaning
Flying the airplane. Keeping it right-side up, going where you want it to go, at the speed and height you want — before worrying about anything else.
Full Definition
The act of physically flying the aircraft — controlling its attitude, altitude, airspeed, and flight path. In the pilot priority phrase 'aviate, navigate, communicate,' aviating is the first and highest priority: keep the aircraft under control before doing anything else.
Context Anchor
Often encountered in the priority phrase aviate, navigate, communicate, especially when the pilot is busy, distracted, or handling a problem.
Derivation
From the Latin avis, meaning bird. 'Aviate' was coined to describe the act of flying like a bird, and 'aviating' is its present-tense form. The word reminds pilots that their first job, like a bird's, is simply to stay in the air under control.