Synonyms for Miasmic:

adj.

fetid (adjective)
putrid, rank, smelly, fetid, stinking, Effluvial, malodorous, reeking, odorous, sulfurous.
gaseous (adjective)
rarefied, Reeky, vaporous, gaseous, atmospheric, steamy.
infectious (adjective)
mephitic.
odorous (adjective)
putrid, stinking, smelly, malodorous, fetid, reeking.

n.

miasmic (noun)
malodorous, vaporous, miasmal, cloudy, mephitic.

Other synonyms:

Other relevant words:
mephitic, miasmal, cloudy.