Dictionary
hal•o•gen
Pronunciation: (hal'u-jun, -jen", hā'lu-), [key]—
n. Chem.
any of the electronegative elements, fluorine, chlorine, iodine, bromine, and astatine, that form binary salts by direct union with metals.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.