Condition of suit perhaps (4)
I believe the answer is:
case
This clue is a double definition.
'condition' is the first definition.
(case is a kind of condition)
'suit perhaps' is the second definition.
(as in a legal suit or case)
'of' is the link.
(Other definitions for case that I've seen before include "Item of luggage" , "Outer shell" , "Check out" , "Cover" , "A proceeding in a court of law" .)