Old Italian centaurs running amok (8)
I believe the answer is:
etruscan
'old italian' is the definition.
(I've seen this in another clue)
'centaurs running amok' is the wordplay.
'running amok' indicates an anagram.
'centaurs' anagrammed gives 'ETRUSCAN'.
(Other definitions for etruscan that I've seen before include "Pre-Roman Italian" , "Of an ancient people of central Italy" , "of bygone civilisation" , "Sure can't refer to ancient state in Italy" , "Old person" .)