Provice drug? Crack! (5)
I believe the answer is:
equip
'provice' is the definition.
I can't tell whether this defines the answer.
'drug? crack' is the wordplay.
'drug?' becomes 'e' (E is another name for ecstasy).
'crack' becomes 'quip' (both can mean a joke).
'e'+'quip'='EQUIP'
Can you help me to learn more?
(Other definitions for equip that I've seen before include "Fit out, supply" , "Provide with kit" , "Give kit to" , "Accoutre" , "Provide with items (for particular task)" .)