il·​lu·​mi·​nant i-ˈlü-mə-nənt How to pronounce illuminant (audio)
: an illuminating device or substance

Examples of illuminant in a Sentence

at the time, a spermaceti candle was the brightest indoor illuminant available
Recent Examples on the Web Distilling rock oil produced multiple interesting compounds, one of which looked like an ideal illuminant. Charles R. Morris, WSJ, 21 June 2018

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'illuminant.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1644, in the meaning defined above

Time Traveler
The first known use of illuminant was in 1644

Dictionary Entries Near illuminant

Cite this Entry

“Illuminant.” Dictionary, Merriam-Webster, Accessed 26 May. 2024.

Medical Definition


il·​lu·​mi·​nant -nənt How to pronounce illuminant (audio)
: an illuminating device or substance (as for a microscope)
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