Italian horse covers miles (5)
I believe the answer is:
roman
'italian' is the definition.
(Roman is an example)
'horse covers miles' is the wordplay.
'horse' becomes 'roan' (roan is a kind of horse**).
'covers' means one lot of letters goes inside another.
'miles' becomes 'm' (common abbreviation).
'roan' placed around 'm' is 'ROMAN'.
(Other definitions for roman that I've seen before include "Polanski" , "Caesar among others" , "Denizen of the eternal city" , "eg Brutus" , "Sort of face" .)