Belonging to Gurkha, kitbag and military material (5)
I believe the answer is:
khaki
'military material' is the definition.
(I've seen this before)
'belonging to gurkha kitbag and' is the wordplay.
'belonging to' indicates a hidden word (I've seen this in other clues).
'KHAKI' is hidden in the letters of 'gurkha kitbag and'.
(Other definitions for khaki that I've seen before include "Uniform shade" , "Military hue" , "strong fabric" , "Army fabric" , "Army dress material" .)