He is confused by currency in business (9)
I believe the answer is:
franchise
'business' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'he is confused by currency' is the wordplay.
'confused' indicates an anagram.
'by' is a charade indicator (letters next to each other).
'currency' becomes 'franc' (I've seen this before**).
'he'+'is'='heis'
'heis' with letters rearranged gives 'hise'.
'hise' after 'franc' is 'FRANCHISE'.
'in' is the link.
Can you help me to learn more?
(Other definitions for franchise that I've seen before include "rights of citizenship" , "Commercial agreement giving marketing rights" , "For citizen, right" , "Authorisation to engage in specific commercial activity" , "The right to vote in a parliamentary election." .)