pyramids

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.
3. A solid with triangular lateral faces and a polygonal (often square or rectangular) base.
4. A medullary pyramid, the medial-most bumps on the ventral side of the medulla oblongata
5. The game of pool in which the balls are placed in the form of a triangle at spot.
6. A pyramid scheme.
7. Alternative letter-case form of Pyramid. (a solitaire card game)
8. 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.

9. An approximately triangular headline consisting of several centered lines of text of increasing length.

1. To build up or be arranged in the form of a pyramid.
2. To combine (a series of genes) into a single genotype.
3. To employ, or take part in, a pyramid scheme.
4. To engage in pyramid trading.

noun

The game of pyramid pool.