Effluvium

(n.) An invisible, noxious emanation, as of vapor or gas; as, the effluvium from diseased bodies, or from ill drainage.

Thesaurus Entries

afterdamp, aroma, aura, blackdamp, breath, chokedamp, cloud, coal gas, damp, definite odor, detectable odor, ectoplasm, ectoplasy, emanation, essence, exhalation, exhaust, exhaust gas, exteriorized protoplasm, fetid air, firedamp, flatus, flavor, fluid, fragrance, fume, malaria, mephitis, miasma, odor, puff of smoke, redolence, reek, savor, scent, smell, smoke, smudge, spoor, steam, stench, subtle odor, trace, trail, vapor, volatile, water vapor, whiff