Plain English Meaning
An instrument on the panel that shows whether the airplane's nose is pointed up or down, and whether the wings are level or tilted, by comparing the aircraft to a small line representing the horizon.
Full Definition
A gyroscopic flight instrument that displays the airplane's pitch and bank attitude relative to the natural horizon. It uses a spinning gyro mounted so its spin axis stays vertical, providing a stable reference against which the aircraft's movement is shown on a small artificial horizon line. Also known as an attitude indicator or artificial horizon.
Context Anchor
Seen on the instrument panel during flying, , and any time are poor.