Webster's Revised Unabridged Dictionary · 1913

Pox

Pox , noun

[For pocks, Old English pokkes. See Pock. It is plural in form but is used as a singular.]

(Medicine) Strictly, a disease by pustules or eruptions of any kind, but chiefly or wholly restricted to three or four diseases, -- the smallpox, the chicken pox, and the vaccine and the venereal diseases.

Pox, when used without an epithet, as in imprecations, formerly signified smallpox; but it now signifies syphilis.

Pox , transitive verb

To infect with the pox, or syphilis.