[ 'pɪrəmɪd ]
■ noun
1》 a monumental stone structure with a square or triangular base and sloping sides that meet in a point at the top, especially one built as a royal tomb in ancient Egypt.
2》 Geometry a polyhedron of which one face is a polygon and the other faces are triangles with a common vertex.
3》 Anatomy a ~-shaped structure, especially in the brain.
4》 a system of financial growth achieved by a small initial investment.
5》 ( ~s ) [treated as sing. ] a game played on a billiard table with fifteen coloured balls arranged in a triangle and a cue ball.
■ verb chiefly N. Amer. heap or stack in a ~al shape.
Derivatives
~ical -'mɪdɪk(ə)l adjective
~ically adverb
Origin
ME: via L. from Gk puramis , puramid- .