The Collaborative International Dictionary
Douglas Harper's Etymology Dictionary
mesel
"leprous" (adj.); "a leper" (n.); both c.1300, from Old French mesel "wretched, leprous; a wretch," from Latin misellus "wretched, unfortunate," as a noun, "a wretch," in Medieval Latin, "a leper," diminutive of miser "wretched, unfortunate, miserable" (see miser). Also from Latin misellus are Old Italian misello "sick, leprous," Catalan mesell "sick."
Wiktionary
mesel
a. (context obsolete English) Having leprosy; leprous. (14th-17th c.) n. 1 (context obsolete English) A leper. (14th-16th c.) 2 (context obsolete English) A wretched or revolting person. (14th-16th c.) 3 (context obsolete English) leprosy. (15th-16th c.)