Business policy (4)
I believe the answer is:
line
I believe this clue is a double definition.
'business' is the first definition.
(synonyms)
'policy' is the second definition.
(as in the party line)
(Other definitions for line that I've seen before include "Railway track; wrinkle" , "Dress" , "(Skin) wrinkle; limit" , "Fill" , "It's long relative to its width" .)