1. (n.)halogen any of the electronegative elements, fluorine, chlorine, iodine, bromine, and astatine, that formbinary salts by direct union with metals.
1. (noun)halogen an electro-negative element or radical, which, by combination with a metal, forms a haloid salt; especially, chlorine, bromine, and iodine; sometimes, also, fluorine and cyanogen. See Chlorine family, under Chlorine
Definitions of halogen 
