prism

Learned borrowing from Late Latin prisma (“(geometry) prism”), from Ancient Greek πρίσμᾰ (prísmă, “anything sawn; sawdust; (Koine, geometry) prism”), from πρῐ́ζω (prĭ́zō) (a variant of πρῑ́ω (prī́ō, “to saw”), further etymology unknown) + -μᾰ (-mă, suffix forming neuter nouns denoting the effect or result of an action, etc.).