n. Chem. a non-metallic element occurring naturally in various metallic sulphide ores and characterized by the variation of its electrical resistivity with intensity of illumination.
Usage:
Symb.: Se.
Phrases and idioms:
selenium cell a piece of this used as a photoelectric device.
Derivatives:
selenate n. selenic adj. selenious adj.
Etymology: mod.L f. Gk selene moon + -IUM