Society member in black suit (4)
I believe the answer is:
club
I believe this clue is a triple definition!
'society' is the first definition.
(I know that society can be written as club)
'member' is the second definition.
(club member is a kind of member)
'in' is a link.
'black suit' is the third definition.
(Other definitions for club that I've seen before include "Dance venue" , "Staff - association" , "Association for people with common interest" , "Batter" , "See 1" .)