I. ˈpir-ə-ˌmid noun
Etymology: Latin pyramid-, pyramis, from Greek
Date: 1549
1.
a. : an ancient massive structure found especially 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 — see volume table
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 pyramid
• py·ra·mi·dal pə-ˈra-mə-d ə l, ˌpir-ə-ˈmi- adjective
• py·ra·mi·dal·ly adverb
• pyr·a·mid·i·cal ˌpir-ə-ˈmi-di-kəl adjective
[
pyramid 2
]
II. verb
Date: circa 1900
intransitive verb
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
transitive verb
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