Bowler's approach (3-2)
'bowler's approach' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for run-up that I've seen before include "Preliminary period" , "Cricketing approach?" , "Approach - preliminaries" , "Bowler's approach?" .)
(Another definition for runup that I've seen is " Having hoisted".)