Plain English Meaning
An instrument that tells the pilot how fast the airplane is turning, not how far it has turned. It uses a small spinning wheel inside the instrument to sense the rate of the turn.
Full Definition
A flight instrument that uses a spinning gyroscope to measure how quickly the aircraft is turning about its vertical axis, displayed in degrees per second or as a standard-rate reference. A standard-rate turn shown on this instrument equals 3 degrees per second, which completes a 360-degree turn in two minutes.
Context Anchor
Seen on the instrument panel during instrument flying, especially when a pilot must or a turn without using outside .