The state of being infected with harmful bacteria.
Septicity is very bad and can make people very sick.
Examples:
The septicity of the water made everyone sick.
The doctor checked for septicity in the wound.
Septicity in the food made me feel very bad.
The septicity of the swamp water was so bad, even the animals wouldn't drink it.
The septicity of the old, dirty pond was so bad that nothing could live in it.
The septicity of the air in the old, closed room made everyone cough and feel sick.