Staff Sergeant initially given credit (5)
I believe the answer is:
stick
'staff' is the definition.
(I've seen this before)
'sergeant initially given credit' is the wordplay.
'initially' says to take the initial letters.
'given' is a charade indicator (letters next to each other).
'credit' becomes 'tick' (I've seen this before).
The first letter of 'sergeant' is 's'.
's'+'tick'='STICK'
(Other definitions for stick that I've seen before include "Staff - criticism" , "Gear lever; adhere" , "Glue; piece of wood" , "Tolerate" , "Flak - cling" .)