noun venom; poison.
2. contagion ·noun the transmission of a disease from one person to another, by direct or indirect contact.
3. contagion ·noun the act or means of communicating any influence to the mind or heart; as, the contagion of enthusiasm.
4. contagion ·noun that which serves as a medium or agency to transmit disease; a virus produced by, or exhalation proceeding from, a diseased person, and capable of reproducing the disease.