prism
A geometrical figure with volume counting with a pair of parallel bases.
The most evocative prism has triangular bases (e.g. Post #742744). It is popular because of its ability to create rainbows out of ordinary (polichromatic) light.
Clarification
Cubes are prisms too, but those are better off tagged as cubes.
Pyramids are not prisms.
Aliases: none