Definition of: syphilis

(sif′ə·lis) noun Pathol.
An infectious, chronic, venereal disease caused by a spirochete (Treponema pallidum) transmissible by direct contact or congenitally. It usually progresses by three stages of increasing severity: primary, secondary, and tertiary. [after Syphilis, sive Morbus Gallicus, a Latin poem by Fracastoro, published in 1530, the hero of which, Syphilus, a shepherd, was the first sufferer from the disease]
—syph′i·loid, syph′·i·lous adjective