Ball balancers (4)
I believe the answer is:
tees
'ball balancers' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tees that I've seen before include "Northern river" , "River in NE England" , "Starting places on the golf course" , "Middlesbrough's river" , "Golfer's equipment" .)