Real Dictionary

prism
If you see something through a prism of something such as time or memory, your idea of it is affected by that thing.
countable noun: A prism is a block of clear glass or plastic which separates the light passing through it into different colours.

prism in American English
a solid figure whose ends are parallel, polygonal, and equal in size and shape, and whose sides are parallelograms
noun: a transparent solid body, often having triangular bases, used for dispersing light into a spectrum or for reflecting rays of light

prism in British English
noun: 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