House these militants guard (4)
I believe the answer is:
semi
'house' is the definition.
(short for semi-detached)
'these militants guard' is the wordplay.
'guard' indicates the answer is hidden within the clue (I've seen 'guards' mean this).
'SEMI' is hidden within 'these militants'.
(Other definitions for semi that I've seen before include "Connected house" , "One house of pair" , "Prefix meaning half (4)" , "accommodation" , "eg Half a house" .)