Morbilli: Another name for measles, an acute highly contagious viral disease with fever, runny nose, cough, red eyes, and a spreading skin rash. Also known as rubeola, it is a potentially disastrous disease and can be complicated by ear infections, pneumonia, encephalitis (that can cause convulsions, mental retardation. and even death), the sudden onset of low blood platelet levels with severe bleeding (acute thrombocytopenic purpura) or a chronic brain disease that occurs months to often years after an attack of measles (subacute sclerosing panencephalitis). During pregnancy measles may trigger miscarriages or premature delivery. Measles can be prevented through vaccination. The disease is also called the hard measles and (depending on how long one thinks it lasts) the seven- day measles, the nine-day measles, or the ten-day measles. The name measles comes from the Middle English maselen meaning many little spots, referring to the rash.