An ancient massive construction with a square or rectangular base and four triangular sides meeting in an apex, such as those built as tombs in Egypt or as bases for temples in Mesoamerica.
User Defined Definitions
"a polyhedron having a polygonal base and triangular sides with a common vertex"
"a massive monument with a square base and four triangular sides; begun by Cheops around 2700 BC as royal tombs in ancient Egypt"
"enlarge one's holdings on an exchange on a continued rise by using paper profits as margin to buy additional amounts"
"arrange or build up as if on the base of a pyramid"
"increase rapidly and progressively step by step on a broad base"