Some militant, indigenous terrorists are hostile (4)
I believe the answer is:
anti
'hostile' is the definition.
(thesaurus)
'some militant indigenous terrorists' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'ANTI' is hidden within 'militant indigenous terrorists'.
'are' acts as a link.
(Other definitions for anti that I've seen before include "not favoured" , "Adversary" , "Prefix meaning against" , "Opposed to followers of Hitler" , "Not in favor of" .)