Leader castigated for holding back something so revered (6)
I believe the answer is:
sacred
'revered' is the definition.
(similar in meaning)
'leader castigated for holding back' is the wordplay.
'holding' indicates a hidden word.
'back' says the letters should be written backwards.
'dercas' is hidden in the letters of 'leader castigated for'.
'dercas' backwards is 'SACRED'.
'something so' is the link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for sacred that I've seen before include "Holy, blessed" , "'Consecrated, holy (6)'" , "Sanctified" , "'Hallowed, holy (6)'" , "devoted to deity" .)