Donor putting lock on account after complaint about Nigel's capital (12)
I believe the answer is:
benefactress
'donor' is the definition.
(thesaurus)
'lock on account after complaint about nigel's capital' is the wordplay.
I cannot quite see how this works, but
'lock' could be 'ress' (I've seen this in another clue) and 'ress' is located in the answer.
'account' could be 'ac' (abbreviation) and 'ac' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'putting' is the link.
Can you help me to learn more?
(Other definitions for benefactress that I've seen before include "one who does good" , "Donor, patron" , "Generous female donor" , "One gives" , "Lady patron" .)