1 Chem. a non-metallic element of the halogen group, forming black crystals and a violet vapour, used in medicine and photography, and important as an essential element for living organisms.
Usage:
Symb.: I.
2 a solution of this in alcohol used as a mild antiseptic.
Etymology: F iode f. Gk iodes violet-like f. ion violet + -INE(4)
Useful english dictionary. 2012.