Maple tree output (3)
I believe the answer is:
sap
'maple tree output' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sap that I've seen before include "One is easily fooled" , "Internal tree moisture" , "Deplete, drain of resources" , "Watery substance in a plant" , "dig tunnels" .)