n.pl. (also treated as sing.) 1 a an acute infectious viral disease marked by red spots on the skin. b the spots of measles. 2 a tapeworm disease of pigs.
[ ME masele(s) prob. f. MLG masele, MDu. masel pustule (cf. Du. mazelen measles), OHG masala: change of form prob. due to assim. to ME meser leper ]