A wearing sort of business (3,5)
I believe the answer is:
rag trade
This clue might be a double definition.
'a wearing' is the first definition.
Both the definition and answer are singular nouns.
Perhaps you can see a link between them that I don't see?
'sort of business' is the second definition.
(the clothing industry)
(Other definitions for rag trade that I've seen before include "Slang for the garment industry" , "Informally, the clothing business" , "National winner" , "Clothing business (colloq.)" , "The couture business" .)