Catholic sacrament, one administered in British capital (7)
I believe the answer is:
penance
'catholic sacrament' is the definition.
(I've seen this in another clue)
'one administered in british capital' is the wordplay.
I cannot really see how this works, but
'one' could be 'an' (an apple is one apple) and 'an' is found in the answer.
The remaining letters 'pence' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for penance that I've seen before include "Punishment for wrongdoing, by religion perhaps" , "Hardship" , "Expression of sorrow for sin" , "Self-punishment for sin" , "act of expiation" .)