Net judge's call (3)
I believe the answer is:
let
'net judge's call' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for let that I've seen before include "Permit; lease" , "Allow; tennis fault" , "Reason for scrubbing service" , "Allow, don't hinder" , "Rent out: grant" .)