Diplomat's case (7)
I believe the answer is:
attache
This clue is a double definition.
'diplomat's' is the first definition.
(I've seen this before)
'case' is the second definition.
(I know that attache is a type of briefcase)
(Other definitions for attache that I've seen before include "Tea chat (anag.)" , "Specialist on embassy staff" , "Man with a mission" , "Member of ambassador's staff" , "Junior ambassador" .)