measles (n.)

infectious disease causing eruptions of rose-colored papulae, early 14c., plural of Middle English masel "little spot,"which isperhaps from Middle Dutch masel "blemish" (in plural "measles") or Middle Low German masele, both from Proto-Germanic *mas- "spot, blemish" (source also of Old High German masla "blood-blister," German Masern "measles").

There might have been an Old English cognate, but if so it has not been recorded. "The phonetic development is irregular" [OED] and the form might have been influenced by Middle English mēsel "leprous; a leper; leprosy" (late 13c., obsolete from mid-16c.), which is from Old French mesel and directly from Medieval Latin misellus "a wretch," noun use of an adjective meaning "wretched," a diminutive of Latin miser "unhappy, wretched, pitiable, in distress."