Dictionary.net

any of a group of single-strand RNA viruses including those causing hepatitis non-A non-B and yellow fever

any of a group of arboviruses including those causing hepatitis non-A non-B and yellow fever

A family of RNA viruses, mainly arboviruses, consisting of two genera: ALPHAVIRUS (group A arboviruses), and RUBIVIRUS. Virions are spherical, 60-70 nm in diameter, with a lipoprotein envelope tightly applied to the icosahedral nucleocapsid.