Cagney developed business (6)
I believe the answer is:
agency
'business' is the definition.
(agency is a kind of business)
'cagney developed' is the wordplay.
'developed' is an anagram indicator.
'cagney' anagrammed gives 'AGENCY'.
(Other definitions for agency that I've seen before include "Organisation; intervention" , "Administrative unit" , "Type of business" , "Instrumentality, operation" , "See 24 Across" .)