1. Optical device having a triangular shape and made of glass or quartz; used to deviate a beam or invert an image
   "The science class used an optical prism to demonstrate light refraction";
   - optical prism
    
2. A polyhedron with two congruent and parallel faces (the bases) and whose lateral faces are parallelograms
   "The scientist used a prism to separate white light into its component colours"

Derived forms: prisms

Type of: optical device, polyhedron

Part of: biprism, prism spectroscope, scope [informal], spectroscope, telescope

Encyclopedia: Prism