1. (n.)halogen any of the electronegative elements, fluorine, chlorine, iodine, bromine, and astatine, that form binary salts by direct union with metals.
Etymology: (1835–45)
Definition of 'Halogen'
Princeton's WordNet
1. (noun)halogen any of five related nonmetallic elements (fluorine or chlorine or bromine or iodine or astatine) that are all monovalent and readily form negative ions
Definition of 'Halogen'
Webster Dictionary
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 
