Halogen
Halogen (hal"o*jen) , noun
[Greek "a`ls, "alo`s, salt + -gen: compare French halogène.]
(Chemistry) An electro-negative element or radical, which, by combination with a metal, forms a haloid salt; especially, chlorine, fluorine, bromine, and iodine; sometimes, also cyanogen. See Chlorine family, under Chlorine.