Clever releasing B side (5)
I believe the answer is:
right
'side' is the definition.
'clever releasing b' is the wordplay.
'clever' becomes 'bright' (I've seen this before).
'releasing' is a deletion indicator.
'bright' with 'b' taken away is 'RIGHT'.
(Other definitions for right that I've seen before include "Correct - starboard" , "Morally defensible" , "Authority - one hand" , "It's what you deserve" , "OK?" .)