European actor in a play (8)
I believe the answer is:
croatian
'european' is the definition.
(I know that Croatian is a type of Slav)
'actor in a play' is the wordplay.
'play' indicates anagramming the letters.
'actor'+'in'+'a'='actorina'
'actorina' is an anagram of 'CROATIAN'.
(Other definitions for croatian that I've seen before include "Slavic language" , "Split personality" , "One from Zagreb, say" , "from area in Europe" , "Native to a Balkan republic that became independent in 1991" .)