WordNet (r) 3.0 (2006):

pseudorubella
    n 1: a viral disease of infants and young children;
         characterized by abrupt high fever and mild sore throat; a
         few days later there is a faint pinkish rash that lasts for
         a few hours to a few days [syn: exanthema subitum,
         roseola infantum, roseola infantilis, pseudorubella]