Prisma

Part of speech: noun

Definitions

1. A geometric figure that has two parallel faces and rectangular sides, commonly associated with optics and light refraction
2. An object that disperses light into its component colors, often triangular in shape and used in scientific experiments
3. A medium that transforms and separates wavelengths of light for various applications, including artistic and scientific purposes

Etymology: The name comes from a verb for sawing. In ancient Greek, "prizein" meant "to saw," and "prisma" was something sawn off, a piece cut from a larger body. Geometers kept that physical sense when they used the term for a solid with flat sides and two matching ends, the shape a sawn-off block would take. The optical meaning came later, from the shape's ability to bend light. Light slows and bends as it enters glass, and different colors bend by different amounts. A glass wedge therefore spreads white light into a band of hues. The term once named a cut-off solid, and now it names a tool that splits light, though the Greek word had nothing to do with light.

Synonyms: prism