a principal branch of the Indo-European family of languages, generally divided into (Russian, Ukrainian, Belorussian), (Old Church Slavonic, Bulgarian, Serbo-Croatian, Slovenian, Macedonian), and (Polish, Lusatian, Czech, Slovak)
See Slavic in American Heritage Dictionary 4
adjective
Of or relating to the Slavs or their languages.
Of or relating to the branch of the Indo-European language family that includes such languages as Russian, Serbo-Croatian, and Polish, and is composed of the East Slavic, South Slavic, and West Slavic subdivisions.