- a contrivance, consisting of a ring or base on an axis, that permits an object, as a ship's compass, mounted in or on it to tilt freely in any direction, in effect suspending the object so that it will remain horizontal even when its support is tipped.
- a device, consisting of two or three pivoted rings at right angles to each other, that provides free suspension in all planes for an object such as a gyroscope, compass, chronometer, etc
