prism Meaning, Definition & Usage

  1. noun a polyhedron with two congruent and parallel faces (the bases) and whose lateral faces are parallelograms
  2. noun optical device having a triangular shape and made of glass or quartz; used to deviate a beam or invert an image
    optical prism.

WordNet


Prism noun
Etymology
L. prisma, Gr. , fr. , , to saw: cf. F. prisme.
Definitions
  1. (Geom.) A solid whose bases or ends are any similar, equal, and parallel plane figures, and whose sides are parallelograms. Prisms of different forms are often named from the figure of their bases; as, a triangular prism, a quadrangular prism, a rhombic prism, etc.
  2. (Opt.) A transparent body, with usually three rectangular plane faces or sides, and two equal and parallel triangular ends or bases; -- used in experiments on refraction, dispersion, etc.
  3. (Crystallog.) A form the planes of which are parallel to the vertical axis. See Form, n., 13.

Webster 1913