1. Plural of effluvium; a foul or noxious smell or vapor, especially one arising from decaying matter or waste.
Usage: Usually used in plural form; Often refers to invisible or barely visible vapors
2. Invisible emanations or influences believed to flow from a person or object.
Usage: Archaic or literary usage; Often used metaphorically

Examples

• The effluvia from the swamp made the air nearly unbearable during summer.
• Industrial effluvia polluted the river and killed fish downstream.
• The old basement was filled with musty effluvia that suggested years of dampness.
• Effluvia from the landfill drifted across the neighborhood on windy days.
• The doctor warned that disease-carrying effluvia could spread through the crowded tenement.
• Some believed that the effluvia of great artists could inspire those around them.