¹pyramid

noun pyr·a·mid \ˈpir-ə-ˌmid\

: a very large structure built especially in ancient Egypt that has a square base and four triangular sides which form a point at the top

: a shape, object, or pile that is wide near the bottom and narrows gradually as it reaches the top

: something that resembles a pyramid in the way its parts are arranged or organized

Full Definition of PYRAMID

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

: a polyhedron having for its base a polygon and for faces triangles with a common vertex — see volume table

: a crystalline form each face of which intersects the vertical axis and either two lateral axes or in the tetragonal system one lateral axis

: 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

: 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^əl, ˌpir-ə-ˈmi-\ adjective

— py·ra·mi·dal·ly adverb

— pyr·a·mid·i·cal \ˌpir-ə-ˈmi-di-kəl\ adjective

See pyramid defined for English-language learners

See pyramid defined for kids

Illustration of PYRAMID

Origin of PYRAMID

Latin pyramid-, pyramis, from Greek

First Known Use: 1549

Other Archaeology Terms

Attic, Byzantine, Paleolithic, cairn, core, flint, horizon, neolithic, shard, stratum

Rhymes with PYRAMID

arachnid, camelid, giant squid, katydid, ootid, overbid, underbid

²pyramid

verb

Definition of PYRAMID

intransitive verb

: to speculate (as on a security or commodity exchange) by using paper profits as margin for additional transactions

: to increase rapidly and progressively step by step on a broad base

transitive verb

: to arrange or build up as if on the base of a pyramid

: to use (as profits) in speculative pyramiding

: 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

First Known Use of PYRAMID

circa 1900

PYRAMIDAL Defined for Kids

pyramid

noun pyr·a·mid \ˈpir-ə-ˌmid\

Definition of PYRAMID for Kids

: a large structure built especially in ancient Egypt that usually has a square base and four triangular sides meeting at a point and that contains tombs

: a shape or structure with a polygon for its base and three or more triangles for its sides which meet to form the top

Medical Dictionary

pyramid

noun pyr·a·mid \ˈpir-ə-ˌmid\

Medical Definition of PYRAMID

: a polyhedron having for its base a polygon and for faces triangles with a common vertex

: an anatomical structure resembling a pyramid: as a : renal pyramid b : either of two large bundles of motor fibers from the cerebral cortex that reach the medulla oblongata and are continuous with the corticospinal tracts of the spinal cord c : a conical projection making up the central part of the inferior vermis of the cerebellum