Uncompromising business (4)
I believe the answer is:
firm
This clue is a double definition.
'uncompromising' is the first definition.
(thesaurus)
'business' is the second definition.
(I know that firm is a type of business)
(Other definitions for firm that I've seen before include "Solid; secure" , "Company; steady" , "corporation?" , "Unflinching" , "Well-established - business" .)