Synonyms for Miasmic (same or very similar meaning)
WordNet sense 1 (of noxious stench from atmospheric pollution):
mephiticWordNet sense 2 (having an unpleasant smell):
malodorous, stinky, malodourous, ill-smelling, unpeasant-smellingWordNet sense 3 (filled with vapor):
vaporous, miasmal, vapourousWordNet sense 4 (full of or covered with clouds):
cloudyFrom the ODE community, based on WordNetadd/edit