WordNet (r) 3.0 (2006):

atomic number 34
    n 1: a toxic nonmetallic element related to sulfur and
         tellurium; occurs in several allotropic forms; a stable
         grey metallike allotrope conducts electricity better in the
         light than in the dark and is used in photocells; occurs in
         sulfide ores (as pyrite) [syn: selenium, Se, atomic
         number 34]