Definition from Wiktionary, the free dictionary
prism (plural prisms)
- (geometry) A polyhedron with parallel ends of the same size and shape, the other faces being parallelogram-shaped sides.
- A transparent block in the shape of a prism (typically with triangular ends), used to split or reflect light.
- A crystal in which the faces are parallel to the vertical axis.
geometry: polyhedron with parallel ends of the same size and shape
block used to split or reflect light