Business interest (7)
I believe the answer is:
concern
I believe this is a double definition.
'business' is the first definition.
('concern' can be a synonym of 'business')
'interest' is the second definition.
(concern is a kind of interest)
(Other definitions for concern that I've seen before include "Business - anxiety" , "Firm - interest" , "Affect; solicitude" , "Involve" , "Business - worry" .)