Word Study
planisphere
CIDE DICTIONARY
The representation of the circles of the sphere upon a plane; especially, a representation of the celestial sphere upon a plane with adjustable circles, or other appendages, for showing the position of the heavens, the time of rising and setting of stars, etc., for any given date or hour. [1913 Webster]
OXFORD DICTIONARY
planisphere, n. a map formed by the projection of a sphere or part of a sphere on a plane, esp. to show the appearance of the heavens at a specific time or place.
Derivative
planispheric adj.
Etymology
ME f. med.L planisphaerium (as PLANE(1), SPHERE): infl. by F planisph{egrave}re
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