[1] : The Collaborative International Dictionary of English v.0.48

halogen \hal"ogen\ ha^l"-oje^n, n. gr. "a`ls, "alo`s,
   salt + -gen: cf. f. halog`ene. 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.
   1913 webster
see also:
chlorine family chlorine 

[2] : WordNet (r) 2.0

halogen
     n : any of five related nonmetallic elements fluorine or
         chlorine or bromine or iodine or astatine that are all
         monovalent and readily form negative ions

Halogen >> H Words
Halogen, definition of term: Halogen
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