pyramid

Etymology

From French pyramide, from Old French piramide, from Latin pȳramis, pȳramidis, from Ancient Greek πῡραμίς (pūramís), possibly from πῡρός (pūrós, “wheat”) + ἀμάω (amáō, “reap”) or from Egyptian pr-m-ws (“height of a pyramid”), from pr (“(one that) comes forth”) + m (“from”) + ws (“height”). Schenkel and K. Lang proposed hypothetical Coptic ⲡⲓⲣⲁⲙ (piram) or ⲫⲣⲁⲙ (phram) derived from Egyptian mr via metathesis as a source of πῡραμίς (pūramís) while Schenkel also suggested it being the source of Arabic هرم although the latter is considered far-fetched by Takacs.

noun

1. 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.
2. A construction in the shape of a pyramid, usually with a square or rectangular base.
   [T]he owners of Doddington Hall, in Lincolnshire, have brought the folly into the 21st century, by building a 30ft pyramid in the grounds of the Elizabethan manor. 7 September 2014, “Doddington's garden pyramid is a folly good show: The owners of a Lincolnshire stately home have brought the folly into the 21st century, by building a 30ft pyramid [print edition: Great pyramid of Lincolnshire, 6 September 2014, p. G2]”, in The Daily Telegraph, London
3. (geometry) A solid with triangular lateral faces and a polygonal (often square or rectangular) base.
4. (by extension) Any structure or diagram with many members at the bottom and progressively fewer towards the top.
   The company was organized as a pyramid, with a CEO in charge of four directors, each heading up a department.
   They sit looking at the empty plate that had held a pyramid of sesame cakes. They have eaten them all. 1960, John Updike, 'Rabbit, Run', page 63
5. (neuroanatomy) A medullary pyramid, the medial-most bumps on the ventral side of the medulla oblongata
6. (UK, dated) The game of pool in which the balls are placed in the form of a triangle at spot.
7. A pyramid scheme.
8. (card games, uncountable) Alternative letter-case form of Pyramid. (a solitaire card game)
9. (card games) The triangular layout of cards in the game of Pyramid.
   Build your pyramid with all cards face down, except the cards in the bottom row.
10. (journalism) An approximately triangular headline consisting of several centered lines of text of increasing length.
    […] with a cross-line banner, a set of two-column pyramids beneath it in the middle, and on each side of these exactly the same thing,—something between a headline and a story—"$50,000 Reward for—" etc. 1924, Helen Ogden Mahin, The Development and Significance of the Newspaper Headline

verb

1. To build up or be arranged in the form of a pyramid.
   The paint was stacked in neatly pyramided lots along the concrete floor. 1952, Ralph Ellison, Invisible Man, Penguin Books (2014), page 198
2. (transitive, genetics) To combine (a series of genes) into a single genotype.
3. (intransitive) To employ, or take part in, a pyramid scheme.
4. (finance) To engage in pyramid trading.
   Multiply this by the number of shares you traded, and add other positions if you pyramided. 2002, Alexander Elder, Come Into My Trading Room: A Complete Guide to Trading, page 152
5. (dated) To increase to or towards a peak.