Payment method recalled with sovereign, a coin of old (7)
I believe the answer is:
drachma
'coin of old' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'payment method recalled with sovereign a' is the wordplay.
'payment method' becomes 'card' (card payment).
'recalled' shows that the letters should be reversed in order (to recall can mean to bring something back).
'with' means one lot of letters go next to another.
'sovereign' becomes 'HM' (His or Her Majesty).
'card' backwards is 'drac'.
'drac'+'hm'+'a'='DRACHMA'
Can you help me to learn more?
(Other definitions for drachma that I've seen before include "Former Greek currency unit" , "European currency replaced by the euro in 2002" , "Old Greek currency" , "Old brass" , "ready" .)