Merriam-Webster Collegiate Dictionary - leprosy

 noun  Etymology: Middle English lepruse, from leprous  Date: 15th century  1. a chronic infectious disease caused by a mycobacterium (Mycobacterium leprae) affecting especially the skin and peripheral nerves and characterized by the formation of nodules or macules that enlarge and spread accompanied by loss of sensation with eventual paralysis, wasting of muscle, and production of deformities — called also Hansen's disease  2. a morally or spiritually harmful influence  • leprotic adjective