1. A solid body standing on a triangular, square, or polygonal base, and terminating in a point at the top; especially, a structure or edifice of this shape.
2. (Science: geometry) A solid figure contained by a plane rectilineal figure as base and several triangles which have a common vertex and whose bases are sides of the base.
3. The game of pool in which the balls are placed in the form of a triangle at spot.
(Science: geometry) altitude of a pyramid a pyramid whose axis is perpendicular to the base.
Origin: L. Pyramis, -idis, fr. Gr, of Egyptian origin: cf. F. Pyramide.