<p><strong>Noun</strong></p><ul><li>(in ancient Egypt) a quadrilateral masonry mass having smooth, steeply sloping sides meeting at an apex, used as a tomb.</li><li>(in ancient Egypt and pre-Columbian Central America) a quadrilateral masonry mass, stepped and sharply sloping, used as a tomb or a platform for a temple.</li><li>anything of such form.</li><li>a number of persons or things arranged or heaped up in this manner: a pyramid of acrobats; a pyramid of boxes.</li><li>a system or structure resembling a pyramid, as in hierarchical form.</li><li>(Geometry) a solid having a polygonal base, and triangular sides that meet in a point.</li><li>(Crystallography) any form the planes of which intersect all three of the axes.</li><li>(Anatomy, Zoology) any of various parts or structures of pyramidal form.</li><li>pyramid scheme (def).</li><li>a tree pruned or trained to grow in conical form.</li><li>pyramids, (used with a singular verb) British. a form of pocket billiards for two or four players in which 15 colored balls, initially placed in the form of a triangle, are pocketed with one white cue ball.</li></ul><p><strong>Verb</strong></p><ul><li>(used without object) to take, or become disposed in, the form of a pyramid.</li><li>(in speculating on margin) to enlarge one's operations in a series of transactions, as on a continued rise or decline in price, by using profits in transactions not yet closed, and consequently not yet in hand, as margin for additional buying or selling in the next transaction.</li><li>to increase gradually, as with the completion of each phase: Our problems are beginning to pyramid.</li><li>(used with object) to arrange in the form of a pyramid.</li><li>to raise or increase (costs, wages, etc.) by adding amounts gradually.</li><li>to cause to increase at a steady and progressive rate: New overseas markets have pyramided the company's profits.</li><li>(in speculating on margin) to operate in, or employ in, pyramiding.</li></ul>