[n] a massive memorial with a square base and four triangular sides; built as royal tombs in ancient Egypt
[n] a polyhedron having a polygonal base and triangular sides with a common vertex
[v] increase rapidly and progressively step by step on a broad base
[v] arrange or build up as if on the base of a pyramid
[v] use or deal in (as of stock or commercial transaction) in a pyramid deal
[v] enlarge one's holdings on an exchange on a continued rise by using paper profits as margin to buy additional amounts