Flash subordinate? (6)
I believe the answer is:
second
This clue is a double definition.
'flash' is the first definition.
(thesaurus)
'subordinate?' is the second definition.
(thesaurus)
(Other definitions for second that I've seen before include "Back-up; short time" , "honours degree" , "bit" , "Attendant in a duel or boxing match" , "Formally support, endorse" .)