The English word vampire was borrowed from French vampire in turn borrowed in early 18th century from Serbian ??????/vampir, or, according to some sources, from Hungarian vampir. The Serbian and Hungarian forms have parallels in virtually all Slavic languages: German (vampir) Bulgarian ?????? (vampir), ????? (vapir) or ?????, Czech and Slovak upir, Polish wapierz and (perhaps East Slavic-influenced) upior, Russian ????? (upyr' ), Belarussian ??i? (upyr), Ukrainian ????? (upir' ), from Old Russian ????? (upir' ).

The word Upir as a term for vampire is found for the first time in written form in 1047 in a letter to a Novgorodian prince referring to him as 'Upir Lichyj' (Wicked Vampire in Old Russian).

Tracing the source of 'upir' and its   Slavic cognates (i.e., upior, obyrbi, upirbi, obiri) is even   more controversial. Among the proposed proto-Slavic forms are opyr? and opir?. Franz Miklosich, a late 19th century linguist, suggested that 'upir' is derived from 'uber', a Turkish word for  'witch' (cf. Kazan Tatar ubyr "witch"). Andre Vaillant suggests just the opposite -- that the   Northern Turkish word 'uber' derived from the Slavic 'upir'. More recently, Jan Perkowski, who has done a great amount of   research on the vampires of the Slavs, also favors a Slavic origin to the word.

But even amongst those who lean towards a Slavic origin, there is considerable disagreement.  Kazimierz Moszynski suggests that   'u-pir' is from a Serbo-Croatian word 'pirati' (to blow). Aleksandr Afanas'ev points to the Slavic 'pij' (to drink), which may have entered the Slavic language from the Greek, via Old Church Slavonic. The Slavic word might, like its possible Russian cognate netopyr' ("bat"), come from the Proto-Indo-European root for "to fly".