Definition of: pyramid

(pir′ə·mid) noun
1. Archit. A solid structure of masonry with a square base and triangular sides meeting in an apex. Such structures were used as tombs or temples. The pyramids of Egypt, raised over the sepulchral chambers of kings, are the best examples. The most interesting group is at Giza, near Cairo. The pyramids of Mexico served as temples. The largest is the pyramid near Cholula on the Pueblo plateau, in central Mexico.
2. Something in pyramidal form.
3. Geom. A solid consisting of a polygonal base and triangular sides, the apices of the triangles coming together at the vertex.
4. Mineral. A crystal form consisting of three or more similar planes having a common point of intersection.
5. Physiol. One of various pyramidal or conical structures found in animal organisms.
6. Anat. A small bony projection in the cavity of the tympanum.
7. Any tree trained in pyramidal form.
8. The operations involved in pyramiding.
—v.t. & v.i.
1. To arrange or form in the shape of a pyramid.
2. To buy or sell (stock) with paper profits shown by the change in price of stock already purchased or sold, without any additional deposit of money being made, and to continue so buying or selling on each movement in price. [<F pyramide <L pyramis, -idis <Gk. pyramis, -idos, prob. <Egyptian pi–mar a pyramid]
THE PYRAMIDS AT GIZA