Effluvium

Ef‐flu″vi‐um (?), n.; pl.Effluvia (#). [L., a flowing out, fr. effluere to flow out. See Effluent, a.] Subtile or invisible emanation; exhalation perceived by the sense of smell; especially, noisome or noxious exhalation; as, the effluvium from diseased or putrefying bodies, or from ill drainage.