miasma
noun·/maɪˈæz.mə/
1. A foul, unhealthy vapor once believed to arise from decay and to cause disease; “bad air” as medical explanation (historical; scientific).
The city blamed the fever on miasma from the marshes, as if sickness were simply something you could smell.
2. A stifling or corrupting atmosphere, literal or figurative, that seems to seep from a place, an era, or a moral condition (literary).
A miasma of resentment hung over the meeting, thick enough to taste.
Etymology
From Greek míasma “pollution, defilement,” from miainein “to stain.” The word began as moral contamination and became environmental theory; later science corrected the cause, but the metaphor endured because the feeling is real.
Related Words
effluviuman emanation or odor; often less ominous
pestilencedisease; the feared result
contagionthe modern mechanism; once wrongly displaced by miasma
taintthe older moral sense in plain dress