Plān'i-sphēre, n.

[Fr. planisphēre, It. & Sp. planisferio, N. Lat. planisphærium, from Lat. planus, plane, and sphæra, sphere.]

1. The representation of the circles of the sphere upon a plane.
2. 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, &c., for any given date or hour.