prism

noun prisms

1. An object having the shape of a geometrical prism (sense 1).
2. A cutting (“open passage at a level lower than the surrounding terrain, dug for a canal, railway, or road to go through”) or an embankment shaped like a prism (sense 1) or a number of prisms, such that its volume can be easily calculated.
3. A crystal in which the faces are parallel to the vertical axis.
4. A transparent block in the shape of a prism (sense 1), typically with triangular ends, used to reflect or refract light. [page 13] One of theſe Parts [of a piece of black paper] I painted vvith a red Colour and the other vvith a blevv. […] This Paper I vievved through a Priſm of ſolid Glaſs, vvhoſe tvvo Sides through vvhich the Light paſſed to the Eye vvere plane and vvell poliſhed, and contained an Angle of about Six
5. archaic A spectrum produced by light being refracted through a prism. The beams, that thro' the Oriel shine, / Make prisms in every carven glass, […]
6. broadly A retroreflector (“device which reflects light back to its source with minimal scattering”) which is usually attached to a surveying pole as a target for a total station which emits a light beam at the device and calculates how long it takes to be reflected back in order to measure distance.
7. figuratively A perspective that colours one's perception. I had surveyed the landscape through the prism of poetry, which tinged every object with the hues of the rainbow.