Bantu warriors: two grabbing member of parliament (4)
I believe the answer is:
impi
'bantu warriors' is the definition.
(Zulu or Bantu term)
'two grabbing member of parliament' is the wordplay.
'two' becomes 'II' (Roman numerals).
'grabbing' is an insertion indicator.
'member of parliament' becomes 'MP' (abbreviation).
'ii' going around 'mp' is 'IMPI'.
(Other definitions for impi that I've seen before include "Warrior group" , "group of soldiers" , "armed warriors" , "group of fighting men" , "Band of Zulu warriors" .)