astrolabe

1. (Astron.) An instrument for observing or showing the positions of the stars. It is now disused. Note: Among the ancients, it was essentially the armillary sphere. A graduated circle with sights, for taking altitudes at sea, was called an astrolabe in the 18th century. It is now superseded by the quadrant and sextant. 2. A stereographic projection of the sphere on the plane of a great circle, as the equator, or a meridian; a planisphere. Whewell.

Source: Webster's Revised Unabridged Dictionary (1913), United States public domain. See methodology for full licensing detail. Word validity for game play may differ from any official game dictionary.