pris‧m /ˈprɪzəm/ noun [countable]
[Date: 1500-1600; Language: Late Latin; Origin: prisma, from Greek, 'something cut with a saw'; because of its shape]

1. a transparent block of glass that breaks up white light into different colours

2. technical a solid object with matching ends and several sides which are the same width all the way up

[TahlilGaran] Dictionary of Contemporary English ▲