Sum advanced by Chelsea's Mason? (6)
I believe the answer is:
amount
'sum' is the definition.
(synonyms)
'advanced by chelsea's mason?' is the wordplay.
I cannot quite see how this works, but
'advanced' could be 'a' and 'a' is present in the answer.
The remaining letters 'mount' is a valid word which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for amount that I've seen before include "value" , "Add up or be equivalent to" , "Measure, quantity" , "Total or extent" , "Size" .)