A fixed compass card on which bearings relative to a ship's heading are taken.
a tool accustomed simply take a bearing on a distant item.
An instrument just like a mariner's compass, but without magnetic needles, and achieving two picture vanes where bearings tend to be taken, esp. such as for instance can't be taken because of the compass.
Nautical, a musical instrument for detecting errors associated with compass by the bearings of celestial objects.