prism

American  

[priz-uhm] / ˈprɪz əm /

noun

1. Optics. a transparent solid body, often having triangular bases, used for dispersing light into a spectrum or for reflecting rays of light.

2. Geometry. a solid having bases or ends that are parallel, congruent polygons and sides that are parallelograms.

3. Crystallography. a form having faces parallel to the vertical axis and intersecting the horizontal axes.

---

prism British  

/ ˈprɪzəm /

noun

1. a transparent polygonal solid, often having triangular ends and rectangular sides, for dispersing light into a spectrum or for reflecting and deviating light. They are used in spectroscopes, binoculars, periscopes, etc

2. a form of crystal with faces parallel to the vertical axis

3. maths a polyhedron having parallel, polygonal, and congruent bases and sides that are parallelograms

---

prism Scientific  

/ prĭz′əm /

1. A geometric solid whose bases are congruent polygons lying in parallel planes and whose sides are parallelograms.

2. A solid of this type, often made of glass with triangular ends, used to disperse light and break it up into a spectrum.

3. A crystal form having 3, 4, 6, 8, or 12 faces parallel to the vertical axis and intersecting the horizontal axis.

---

prism Cultural  

1. A solid figure in geometry with bases or ends of the same size and shape and sides that have parallel edges. Also, an object that has this shape.

---

Discover More

A prism of glass (or a similar transparent material) can be used to bend different wavelengths of light by different amounts through refraction. This bending separates a beam of white light into a spectrum of colored light.

Etymology

Origin of prism

1560–70; < Late Latin prīsma < Greek prîsma literally, something sawed, akin to prī́zein to saw, prīstēs sawyer

Explanation

In geometry, a prism is a three-dimensional shape that has two bases that are parallel and the same size and shape. The prism's sides are all parallelograms. A classic pup tent is a triangular prism. In optics, a prism is a piece of glass, quartz, plastic, or other material that can be used to refract light. A typical prism is triangular in shape, and when white light (like sunlight) is shown through it, the prism breaks the light into separate colors and displays it as a rainbow (color spectrum). Sir Isaac Newton experimented with prisms in the 1600s, and his work was the beginning of the modern period of both optics and the understanding of light.

Example Sentences

This structure consists of closely spaced parallel strips that interact with light similarly to a prism.

From Science Daily • Apr. 5, 2026

Bond traders mostly agree that the Fed sees the current situation through that prism: An ounce of prevention now is worth a pound of cure.

From The Wall Street Journal • Mar. 18, 2026

Much of EU policymaking is now being viewed through the prism of sovereignty.

From Barron's • Feb. 5, 2026

It feels so wonderful to get this for a movie that was made so organically and rose up through not through the prism of business, but through the prism of friendship.

From Los Angeles Times • Jan. 22, 2026

Lawrence viewed the quest for 94 through a double prism.

From "Big Science" by Michael Hiltzik