Bloke coming across mile title holder (5)
I believe the answer is:
champ
'title holder' is the definition.
(I've seen this in another clue)
'bloke coming across mile' is the wordplay.
'bloke' becomes 'chap' (both can mean a man).
'coming across' indicates putting letters inside.
'mile' becomes 'm' (common abbreviation).
'chap' placed around 'm' is 'CHAMP'.
(Other definitions for champ that I've seen before include "Title holder (abbr)" , "Fret impatiently; winner" , "Masticate, gnaw" , "Supreme competitor" , "use teeth?" .)