halogen
Pronunciation:
/ˈheɪ.lə.d͡ʒən//ˈhæ.lə.d͡ʒən/noun
Definitions
Any element of group 17, i.e. fluorine, chlorine, bromine, iodine and astatine, which form a salt by direct union with a metal.
A light fixture in which the filament is surrounded by an atmosphere of a halogen gas,