Business not yielding to pressure (4)
I believe the answer is:
firm
I believe this is a double definition.
'business' is the first definition.
(firm is a kind of business)
'not yielding to pressure' is the second definition.
(I've seen this before)
(Other definitions for firm that I've seen before include "commercial partnership" , "Not soft or yielding to pressure" , "Solid; secure" , "'Solid, unyielding (4)'" , "Well-established - business" .)