Word Study
illuminant
CIDE DICTIONARY
illuminant, n. [L. illuminans, -antis, p. pr. of illuminare.].
That which illuminates or affords light; as, gas and petroleum are illuminants. Boyle. [1913 Webster]
OXFORD DICTIONARY
illuminant, n. & adj.
--n. a means of illumination.
--adj. serving to illuminate.
--n. a means of illumination.
--adj. serving to illuminate.
Derivative
illuminance n.
Etymology
L illuminant- part. stem of illuminare ILLUMINATE
THESAURUS
illuminant
aglow, beaming, beamy, benzine, blushing, bright and sunny, burning, candescent, candle, coal oil, electric light bulb, electricity, fire, flame, flushing, gas, gasoline, gleaming, gleamy, glim, glinting, glowing, illuminating, illuminating gas, illuminative, illuminator, illumining, incandescent, incandescent body, irradiative, kerosene, lamp, lamping, lantern, light, light as day, light bulb, light source, luciferous, lucific, luciform, luminant, luminary, luminative, luminiferous, luminificent, luminous, lustrous, match, moon, oil, orient, paraffin, petrol, petroleum, radiant, rutilant, rutilous, shining, shiny, source of light, starbright, starlike, starry, stars, streaming, suffused, sun, sunny, sunshiny, taper, torchFor further exploring for "illuminant" in Webster Dictionary Online