Dejan

Gender	Male
Word/name	Slavic
Region of origin	Balkans
Variant form(s)	Dejana (f.)
Related names	Desa, Desislav, Desimir

Dejan ([dɛjan]; Serbian: Дејан) is a South Slavic masculine given name, derived from the Old Slavic word dejati, meaning "action; to act, to do". It is possible that the name is a diminutive of dithematic Desimir or Desislav, with des meaning "to happen". It is interesting that, although it is considered old Slavic name, some claim name Dejan comes from old Latin word Deus or Dea which mean God or Godly. It is very common in Serbia and Macedonia, and also common in Bulgaria, Montenegro, Bosnia and Herzegovina, Croatia, and Slovenia.

The given name Dejan and the surname Dejanović is unusually widespread in the Serbo-Croatian linguistical area, and it is first mentioned in the mid-14th century, in Serbia.Dejan (fl. 1346–ca. 1366) was a Serbian magnate in the Serbian Empire. The form Dejaniš is also found in the 14th century. According to medieval texts, Dejan was widespread in Serbian lands, and it is frequent in Serbian epic poetry. The name is among the most common in Serbia: It was the fifth most given name in the period of 1961–1970 (at 5,61%); first in 1971–1980; ninth in 1981–1990.

...
Wikipedia