Derive clean form of release (11)
I believe the answer is:
deliverance
'release' is the definition.
(I've seen this before)
'derive clean form' is the wordplay.
'form' is an anagram indicator (another form of the letters).
'derive'+'clean'='deriveclean'
'deriveclean' with letters rearranged gives 'DELIVERANCE'.
'of' is the link.
(Other definitions for deliverance that I've seen before include "Liberation, release" , "Recovery from danger" , "Formal pronouncement" , "Formal utterance" , "Salvation" .)