a. 发光的

n. 光源, 发光体

[化] 发光物; 照明剂

[ noun ]
something that can serve as a source of light
<noun.substance>

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.