Business is settled (4)
I believe the answer is:
firm
I believe this clue is a double definition.
'business' is the first definition.
(firm is a kind of business)
'is settled' is the second definition.
('firm' can be similar in meaning to 'settled')
(Other definitions for firm that I've seen before include "'Solid, unyielding (4)'" , "Not soft or yielding to pressure" , "Solid; secure" , "Resolute; company" , "Fixed" .)