I. ˈha-lə-jən noun
Etymology: Swedish, from hal- + -gen
Date: 1842
: any of the five elements fluorine, chlorine, bromine, iodine, and astatine that form part of group VIIA of the periodic table and exist in the free state normally as diatomic molecules
• ha·log·e·nous ha-ˈlä-jə-nəs adjective
II. adjective
Date: 1880
: containing, using, or being a halogen
a halogen lamp