(Med.) A contagious viral febrile disorder commencing with catarrhal symptoms, and marked by the appearance on the third day of an eruption of distinct red circular spots, which coalesce in a crescentic form, are slightly raised above the surface, and after the fourth day of the eruption gradually decline; rubeola. It is a common childhood disease. (plural in form, but used as singular) "Measles commences with the ordinary symptoms of fever."
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