Cunning and wise one departs slowly (3)
I believe the answer is:
sly
'cunning' is the definition.
(I know that cunning can be written as sly)
'wise one departs slowly' is the wordplay.
'wise one' becomes 'owl' (I've seen this in another clue).
'departs' is a deletion indicator.
'slowly' with 'owl' taken away is 'SLY'.
'and' acts as a link.
(Other definitions for sly that I've seen before include "Unpleasantly cunning and secretive" , "Crafty, devious" , "Sneaky" , "'Cunning, wily (3)'" , "Artful" .)