General occupying specific US territory (6)
I believe the answer is:
custer
'general' is the definition.
(I know that Custer is a general)
'occupying specific us territory' is the wordplay.
'occupying' indicates the answer is hidden within the clue (letters for the answer occupy part of the clue).
'CUSTER' can be found hidden inside 'specific us territory'.
(Other definitions for custer that I've seen before include "Ill-fated US general" , "General who died at battle of Little Bighorn" , "General who was killed at the battle of Little Bighorn" , "General ......, massacred at Little Big Horn" , "General killed by Sioux" .)