leper (n.) Look up leper at Dictionary.com
"one afflicted with leprosy," late 14c., from Late Latin lepra, from Greek lepra "leprosy," from fem. of lepros (adj.) "scaly," from leops "a scale," related to lepein "to peel," from lepos, lepis "a scale," from PIE root *lep- (1) "to peel." Originally the word for the disease itself (mid-13c.); because of the -er ending it came to mean "person with leprosy," so leprosy was coined 16c. from adjective leprous.