prism

noun

• a solid geometric figure whose two end faces are similar, equal, and parallel rectilinear figures, and whose sides are parallelograms.
• Optics a glass or other transparent object in prism form, especially one that is triangular with refracting surfaces at an acute angle with each other and that separates white light into a spectrum of colors.
• used figuratively with reference to the clarification or distortion afforded by a particular viewpoint:they were forced to imagine the disaster through the prism of television