Subordinate FBI guy short of fare (8)
I believe the answer is:
underfed
'short of fare' is the definition.
(fare means food)
'subordinate fbi guy' is the wordplay.
'subordinate' becomes 'under' (similar in meaning).
'fbi guy' becomes 'fed' (I've seen this in another clue).
'under'+'fed'='UNDERFED'
(Other definitions for underfed that I've seen before include "deprived of basic need" , "Malnourished" , "Not having enough to eat" , "in a starved condition" , "Too thin?" .)