Halogen

n.

1.

(Chem.) 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.

Noun

1.

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

astatine, At, atomic number 17, atomic number 35, atomic number 53, atomic number 85, atomic number 9, Br, bromine, chlorine, Cl, F, fluorine, group, grouping, I, iodin, iodine