Trees on the bowling green? (4)
I believe the answer is:
wood
'trees on' is the definition.
'wood' can be an answer for 'trees'. I'm unsure of the 'on' bit.
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for wood that I've seen before include "celebrated conductor" , "'Under Milk - - ' (lit.)" , "Large group of trees" , "Trees; club" , "What you might need to play golf" .)