Not worth discussing (4)
I believe the answer is:
moot
'not worth discussing' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for moot that I've seen before include "Subject to dispute" , "Undecided as a debatable point may be" , "Questionable, debatable" , "Propose for discussion" , "raise for discussion" .)