mephitis
     n 1: a poisonous or foul smelling gas emitted from the earth
     2: a distinctive odor that is offensively unpleasant [syn: {malodor},
         {malodour}, {stench}, {stink}, {reek}, {fetor}, {foetor}]
     3: in some classifications: type genus of the subfamily
        Mephitinae [syn: {genus Mephitis}]
Source: WordNet® 2.0