Definition 1 of 2
Plain English Meaning
When you push on a spinning wheel, it doesn't tilt where you pushed it — it tilts at a point a quarter-turn further around in the direction it's spinning. In gyro instruments, precession is also the slow wandering of the indication over time, which is why pilots have to reset them.
Full Definition
The tendency of a spinning rotor (such as a gyroscope) to respond to an applied force as if that force had been applied at a point 90 degrees later in the direction of rotation. In aviation gyroscopic instruments, precession also refers to the gradual drift of the gyro away from its set reference, requiring periodic correction.
Context Anchor
Seen in discussions of gyroscopic instruments and propeller effects, especially during in .