Hal"o*gen (?), n. [Gr. "a`ls, "alo`s, salt + -gen: cf. F. halogene.] Chem.
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.
© Webster 1913.