Rock frontman eviscerated legally with conviction (9)
I believe the answer is:
adamantly
'with conviction' is the definition.
(I've seen this in another clue)
'rock frontman' is the wordplay.
'rock' becomes 'adamant' (I have seen 'Legendary rock' mean 'adamant' so perhaps 'rock' could also mean 'adamant').
'frontman' becomes 'ly' (I can't justify this - if you can you should believe this answer much more).
'adamant'+'ly'='ADAMANTLY'
'eviscerated legally' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for adamantly that I've seen before include "Inflexibly" , "With unshakeable purpose" .)