Stop communicating and no longer have skill (4,5)
I believe the answer is:
lose touch
'stop communicating' is the definition.
(I've seen this before)
'no longer have skill' is the wordplay.
'no longer' becomes 'lose' (I am not sure about this - if you are sure you should believe this answer much more).
'have' is a charade indicator (letters next to each other).
'skill' becomes 'touch' (I've seen this before).
'lose'+'touch'='LOSE TOUCH'
'and' acts as a link.
Can you help me to learn more?
(Other definitions for lose touch that I've seen before include "Fail to maintain contact" , "Stop communicating" .)