from
The Collaborative International Dictionary of English v.0.48
Astrolabe \As"tro*labe\ ([a^]s"tr[-o]*l[=a]b), n. [OE.
astrolabie, astrilabe, OF. astrelabe, F. astrolabe, LL.
astrolabium, fr. Gr. 'astrola`bon; 'a`stron star + ?, ?, to
take.]
1. (Astron.) An instrument for observing or showing the
positions of the stars. It is now disused.
[1913 Webster]
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 It is now superseded by the quadrant and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.
[1913 Webster]
2. A stereographic projection of the sphere on the plane of a
great circle, as the equator, or a meridian; a
planisphere. --Whewell.
[1913 Webster]