Individual delivering a reckoning in the Library? (10)
I believe the answer is:
bookkeeper
'individual' is the definition.
(bookkeeper is a kind of individual)
'a reckoning in the library?' is the wordplay.
I cannot really see how this works, but
'a' could be 'per' (eg 'one a day' means 'one per day') and 'per' is present in the answer.
This explanation may well be incorrect...
'delivering' is the link.
Can you help me to learn more?
(Other definitions for bookkeeper that I've seen before include "Business occupation" , "person responsible for financial oversight" , "Accounts official" , "accountant" , "who works to maintain balance" .)