illuminant

illuminant
    n 1: something that can serve as a source of light
    

Illuminant \Il*lu"mi*nant\, n. [L. illuminans, -antis, p. pr. of
   illuminare.]
   That which illuminates or affords light; as, gas and
   petroleum are illuminants. --Boyle.
   [1913 Webster]
    

72 Moby Thesaurus words for "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, torch