measles
mea.sles \'me--z*lz\ n [ME meseles, pl. of mesel measles, spot characteristic of measles;] [ME mesel infested with tapeworms, lit., leprous, fr. OF, fr. ML misel] pl but sing or pl in constr akin to MD masel spot characteristic of measles 1a: an acute contagious viral disease marked by an eruption of distinct red circular spots 1b: any of various eruptive diseases lus leper, fr. L, wretch, fr. misellus, dim. of miser miserable 2: infestation with or disease caused by larval tapeworms in the muscles an d tissues
Webster's English Dictionary