[pyr.a.mid] n [L pyramid-, pyramis, fr. Gk] (1549) 1 a: an ancient massive structure found esp. in Egypt having typically a square ground plan, outside walls in the form of four triangles that meet in a point at the top, and inner sepulchral chambers b: a structure or object of similar form
2: a polyhedron having for its base a polygon and for faces triangles with a common vertex
3: a crystalline form each face of which intersects the vertical axis and either two lateral axes or in the tetragonal system one lateral axis
4: an anatomical structure resembling a pyramid: as a: any of the conical masses that project from the renal medulla into the kidney pelvis b: either of two large bundles of motor fibers from the cerebral cortex that reach the medulla oblongata and are continuous with the pyramidal tracts of the spinal cord
5: an immaterial structure built on a broad supporting base and narrowing gradually to an apex "the socioeconomic ~" -- py.ra.mi.dal adj -- py.ra.mi.dal.ly adv -- pyr.a.mid.i.cal adj
[2]pyramid vi (ca. 1900) 1: to speculate (as on a security or commodity exchange) by using paper profits as margin for additional transactions
2: to increase rapidly and progressively step by step on a broad base ~ vt 1: to arrange or build up as if on the base of a pyramid
2: to use (as profits) in speculative pyramiding
3: to increase the impact of (as a tax assessed at the production level) on the ultimate consumer by treating as a cost subject to markup