# Definition of prism in English:

## prism

### noun

Geometry
• 1A solid geometric figure whose two ends are similar, equal, and parallel rectilinear figures, and whose sides are parallelograms.

• ‘We will show that the area of this ring is equal to the area of the corresponding cross section of the dome, which implies that the dome and the punctured prism have equal volumes.’
• ‘Volumes of solids such as prisms, pyramids, tetrahedrons, wedges, cylinders and truncated cones are calculated.’
• ‘Ancient stonecutters could thus cleave it perpendicular to the crystal axis to produce hexagonal prisms of any desired length.’
• ‘You can readily extend the same approach to other polyhedra, such as prisms and antiprisms.’
• ‘He goes on to consider solid geometry giving results on prisms, cylinders, and spheres.’
1. 1.1Optics A glass or other transparent object in the form of a prism, especially one that is triangular with refracting surfaces at an acute angle with each other and that separates white light into a spectrum of colours.
• ‘When he passed a thin beam of sunlight through a glass prism Newton noted the spectrum of colours that was formed.’
• ‘By the use of two mirrors, the fluorescence excitation light of 295-nm wavelength was directed perpendicular onto one of the smallest sides of the quartz prism.’
• ‘In their experiments, Descartes, Robert Hooke and Edward Boyle had put a screen close to the other side of the prism and seen that the spot of light came out as a mixture of colour.’
• ‘According to Blondlot, a narrow stream of N-rays was refracted through the prism and produced a spectrum on a field.’
• ‘Newton applied the Method of Analysis to induce the explanatory principle that sunlight comprises rays of differing colours, and that each colour is refracted by the prism through a characteristic angle.’
2. 1.2 Used to refer to the clarification or distortion afforded by a particular viewpoint.
‘they were forced to imagine the disaster through the prism of television’
• ‘So information about her youth is inevitably scarce, apart from her own memoirs, which are bound to be somewhat distorted through the prism of time.’
• ‘Viewed through the Upper West Side prism in which ‘enlightened’ equals ‘liberal,’ there is some truth to this contention.’
• ‘It's a good rule of thumb because seeing a given action through the prism of someone whose motives you are inclined to view favorably is a good check on unwarranted suspicions.’
• ‘From our side of the prism, each and every one of these events is disparate.’
• ‘It is most certainly distorted by the prism of your own arrogance and ignorance.’

### Origin

Late 16th century: via late Latin from Greek prisma ‘thing sawn’, from prizein ‘to saw’.

/ˈprɪz(ə)m/