1. a noxious vapor or fog, especially one believed in the past to cause disease
Usage: historical/archaic; also spelled 'miasma' (plural: miasms or miasmas)
2. a poisonous or corrupting influence or atmosphere
Usage: figurative

Examples

• Medieval doctors believed that miasm rising from swamps caused plague.
• The city's streets were choked with miasm during the cholera outbreak.
• A miasm of suspicion hung over the organization after the scandal.
• The factory released a thick miasm that settled over the neighborhood.
• He tried to escape the miasm of corruption that pervaded the government.
• Scientists eventually disproved the miasm theory of disease transmission.