Definition of illuminant in English:

illuminant

noun

technical
  • A means of lighting or source of light.

    ‘until 1880, oil was the only illuminant in use’
    • ‘When refined into kerosene, it was the only ‘cheap illuminant that burned in a bright, clean, safe manner,’ by far better than blubber and lard.’
    • ‘Yes, there was a market for the refined illuminant.’
    • ‘While in defensive situations illuminants can be most valuable, in offensive situations, their use for surveillance and target acquisition can be counter-productive.’
    • ‘Also, only in the underwater optical environment do the illuminant and background change independently of each other, creating complex problems for crypsis.’
    • ‘However, because the background radiance in the pelagic environment is a complex result of multiple scattering and absorption events, its spectrum changes independently of the illuminant.’
    lamp, light, flashlight, beacon
    View synonyms

adjective

  • Giving off light.

    • ‘Lexx casts an illumination spell so that they can all better see and they continue on with the glowing illuminant orb leading them.’
    • ‘The XM930 contains a standard illuminant mix which provides approximately 1 million candlepower of light whereas the XM983 contains an infrared illuminant mix for use with standard night vision devices.’
    • ‘The owner of the illuminant system was Mr WK Hardacre, of Hellifield House.’
    • ‘Given the illuminant spectrum and the spectral sensitivity functions for the camera, we can calculate the estimates of the weights at each pixel from six sensor outputs.’

Origin

Mid 17th century: from Latin illuminant- ‘illuminating’, from the verb illuminare (see illuminate).

Pronunciation

illuminant

/ɪˈlumənənt//iˈlo͞omənənt/