pan-Slavic
/ˌpanˈslɑːvɪk/adjective
Of, relating to, or involving all Slavs or Slavonic-speaking peoples; of, relating to, or advocating pan-Slavism.
Origin
Mid 19th century; earliest use found in John Gardner Wilkinson (1797–1875), Egyptologist. From pan- + Slavic, perhaps after pan-Slavism. Compare German panslavisch.