pyramidpyr·a·mid (p?r??-m?d)n.1. a. A solid figure with a polygonal base and triangular faces that meet at a common point.b. Something shaped like this polyhedron.2. a. A massive monument of ancient Egypt having a rectangular base and four triangular faces culminating in a single apex, built over or around a crypt or tomb.b. Any of various similar constructions, especially a four-sided Mesoamerican temple having stepped sides and a flat top surmounted by chambers.3. The transactions involved in pyramiding stock.4. Anatomy A structure or part suggestive of a pyramid in shape.v. pyr·a·mid·ed, pyr·a·mid·ing, pyr·a·mids v.tr.1. To place or build in the shape of a pyramid.2. To build (an argument or thesis, for example) progressively from a basic general premise.3. To speculate in (stock) by making a series of buying and selling transactions in which paper profits are used as margin for buying more stock.v.intr.1. To assume the shape of a pyramid.2. To increase rapidly and on a widening base.3. To pyramid stocks.[Latin p?ramis, p?ramid-, from Greek p?ramis, of unknown origin.]py·ram?i·dal (p?-r?m??-dl), pyr?a·mid?ic (-m?d??k), pyr?a·mid?i·cal (-?-k?l) adj.py·ram?i·dal·ly adv.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.pyramid (?p?r?m?d) n1. (Architecture) a huge masonry construction that has a square base and, as in the case of the ancient Egyptian royal tombs, four sloping triangular sides2. an object, formation, or structure resembling such a construction3. (Mathematics) maths a solid having a polygonal base and triangular sides that meet in a common vertex4. (Chemistry) crystallog a crystal form in which three planes intersect all three axes of the crystal5. (Anatomy) anatomy any pointed or cone-shaped bodily structure or part6. (Banking & Finance) finance a group of enterprises containing a series of holding companies structured so that the top holding company controls the entire group with a relatively small proportion of the total capital invested7. (Stock Exchange) chiefly US the series of transactions involved in pyramiding securities8. (Billiards & Snooker) (plural) a game similar to billiards with fifteen coloured ballsvb9. to build up or be arranged in the form of a pyramid10. (Stock Exchange) chiefly US to speculate in (securities or property) by increasing purchases on additional margin or collateral derived from paper profits associated with high prices of securities and property in a boom11. (Banking & Finance) finance to form (companies) into a pyramid Also called (rare): pyramis [C16 (earlier pyramis): from Latin pyramis, from Greek puramis, probably from Egyptian] pyramidal, ?pyra?midical, ?pyra?midic adj py?ramidally, ?pyra?midically advCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014pyr?a?mid (?p?r ? m?d) n. 1. a massive quadrilateral masonry structure having smooth, steeply sloping sides meeting at an apex, as a tomb built in ancient Egypt, or stepped and sharply sloping sides, as a temple platform built in pre-Columbian Central America. 2. any object or arrangement of objects shaped like a pyramid. 3. a system or structure resembling a pyramid, as in hierarchical form. 4. a solid having a polygonal base, and triangular sides that meet in a point. 5. any crystalline form the planes of which intersect all three of the axes. 6. any of various anatomical parts or structures of pyramidal form. 7. the series of transactions involved in pyramiding. v.i. 8. to take, or become disposed in, the form of a pyramid. 9. to speculate in securities trading by using paper profits as margin for additional buying and selling. 10. to increase gradually, as with the completion of each phase. v.t. 11. to arrange in the form of a pyramid. 12. to raise or increase (costs, wages, etc.) by adding amounts gradually. 13. to cause to increase at a steady and progressive rate. 14. to employ in speculative pyramiding. [1590?1600;