a mild, infectious, communicable viral disease, characterized by swollen glands, esp. of the back of the head and neck, and small red spots on the skin; German measles
See rubella in American Heritage Dictionary 4
(ro͞o-bĕlˈə)
noun
A mild contagious eruptive disease caused by a virus and capable of producing congenital defects in infants born to mothers infected during the first three months of pregnancy. Also called German measles.