So we know that name of Macedonia come from the ancient kingdom of Macedonia, and that today Macedonia is mostly Slavs that came in 7/8th century - but they adopted the name of Macedonia (starting many disputes with Greece, but I don't want to talk about that here).
My question is do we know what was the original name these Slavs that settled in the region of Macedonia called themselves? How did others call them, especially Byzantines?
Sclaveni
The Byzantines broadly grouped the numerous Slav tribes living in proximity with the Eastern Roman Empire into two groups: the Sklavenoi and the Antes. The Sclaveni were called as such by Procopius, and as Sclavi by Jordanes and Pseudo-Maurice(Greek: Σκλαβηνοί (Sklabēnoi), Σκλαυηνοί(Sklauēnoi), or Σκλάβινοι (Sklabinoi); Latin: Sclaueni, Sclavi, Sclauini, or Sthlaueni - Sklaveni). The derived Greek term Sklavinia(i)(Σκλαβινίαι; Latin: Sclaviniae) was used for Slav tribes in Byzantine Macedonia and the Peloponnese; these Slavic territories were initially outside of Byzantine control. By 800, however, the term also referred specifically to Slavic mobile military colonists who settled as allies within the territories of the Byzantine Empire. Slavic military settlements appeared in the Peloponnese, Asia Minor, and Italy.