Crown to revise trust (6)
I believe the answer is:
credit
'trust' is the definition.
(crediting is a kind of trusting)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for credit that I've seen before include "Believe, tick" , "Tick - distinction" , "This bank balance is a plus" , "Believe - recognition" , "Favourable balance - good repute" .)