contagion

n. [ L. contagio: cf. F. contagion. See Contact. ] 1. (Med.) The transmission of a disease from one person to another, by direct or indirect contact. [ 1913 Webster ]

☞ The term has been applied by some to the action of miasmata arising from dead animal or vegetable matter, bogs, fens, etc., but in this sense it is now abandoned. Dunglison. [ 1913 Webster ]

And will he steal out of his wholesome bed
To dare the vile contagion of the night? Shak. [ 1913 Webster ]

2. 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. [ 1913 Webster ]

3. The act or means of communicating any influence to the mind or heart; as, the contagion of enthusiasm. “The contagion of example.” Eikon Basilike. [ 1913 Webster ]

When lust . . .
Lets in defilement to the inward parts,
The soul grows clotted by contagion. Milton. [ 1913 Webster ]

4. Venom; poison. [ Obs. ] “I'll touch my point with this contagion.” Shak.

Syn. -- See Infection. [ 1913 Webster ]