Unemployed crew with mischievous potentialities (4,5)
I believe the answer is:
idle hands
'mischievous potentialities' is the definition.
The definition suggests a plural noun which matches the answer.
'unemployed crew' is the wordplay.
'unemployed' becomes 'idle' (associated in meaning).
'crew' becomes 'hands' (I've seen this in another clue).
'idle'+'hands'='IDLE HANDS'
'with' acts as a link.
Can you help me to learn more?
(Another definition for idle hands that I've seen is " 'The devil finds work for . . . . . . . . .'".)