DuckCorp Dico

Found one definition

1.                 From WordNet (r) 3.0 (2006):
                   
   
   
                   
                     
   atomic number 9
       n 1: a nonmetallic univalent element belonging to the halogens;
            usually a yellow irritating toxic flammable gas; a powerful
            oxidizing agent; recovered from fluorite or cryolite or
            fluorapatite [syn: fluorine, F, atomic number 9]