A good half of ground must get trouble (5)
I believe the answer is:
aggro
'trouble' is the definition.
(I've seen this before)
'a good half of ground' is the wordplay.
'a good' becomes 'ag' (I've seen this in other clues).
'half of' means to take half the letters.
'ground' with half the letters taken is 'gro'.
'ag'+'gro'='AGGRO'
'must get' is the link.
(Other definitions for aggro that I've seen before include "Hostile behaviour" , "Yobbish violence" , "Problems and difficulties" , "Grief" , "Greek consumed by past" .)