Returning chums bond for comedy (9)
I believe the answer is:
slapstick
'for comedy' is the definition.
(slapstick is a kind of comedy)
'returning chums bond' is the wordplay.
'returning' says the letters should be written backwards.
'chums' becomes 'pals' ('pal' can be a synonym of 'chum').
'bond' becomes 'stick' (synonyms).
'pals' written backwards gives 'slap'.
'slap'+'stick'='SLAPSTICK'
(Other definitions for slapstick that I've seen before include "Crude form of comedy" , "Knockabout comedy based on action rather than words" , "Humour based on clumsiness" , "unsophisticated humour" , "That's laughable" .)