Emily Dickinson Lexicon

prism, n. [Late L. prisma < Gk πρίσμα, a thing sawn, prism < πρίζιν, to saw.]

1. Triangular geometrical form of transparent glass that refracts light into the colors of the spectrum; [fig.] magnifying glass; instrument which makes the internal beauty of an object visible; device that creates a deceptively beautiful image from the fleeting play of light.
2. [Fig.] ice; crystal; frozen realm; inaccessible region.