Plain English Meaning
The exact path you intend the airplane to follow — the altitude you want to hold, the direction you want to point, and the speed you want to maintain. Anything different from that is a deviation you need to correct.
Full Definition
The specific path through the air that the pilot has chosen or been assigned to fly, defined by a target altitude, heading, airspeed, and attitude. In instrument flying, it is the reference path against which deviations are measured and corrected.
Context Anchor
Seen in instrument flying when the pilot compares the airplane’s actual movement with the path required by a published , an instruction, or a training .