Permission unavailable? You don't say! (5,3)
I believe the answer is:
leave out
'don't say' is the definition.
Although both the answer and definition are verbs in their base form, I cannot understand how one could define the other.
'permission unavailable?' is the wordplay.
'permission' becomes 'leave' (leave is permission or authorisation).
'unavailable?' becomes 'out' (I've seen this in another clue).
'leave'+'out'='LEAVE OUT'
'you' acts as a link.
Can you help me to learn more?
(Other definitions for leave out that I've seen before include "Omit or exclude" , "Forget" , "Omit, overlook" , "not put away" , "Drop" .)