Emily Dickinson Lexicon

PRISM, n. [Fr. prisme; Low L. Sp. and It. prisma; Gr. πρισμα, from πριω, to cut with a saw, to press or strain; Russ. pru.]

A solid whose bases or ends are any similar, equal and parallel plane figures, and whose sides are parallelograms. – D. Olmsted. A trihedral prism of glass is one bounded by two equal and parallel triangular ends and three plain and well polished sides which meet in three parallel lines, running from the three angles of one end to the three angles of the other end. – Newton.