One's beaten by hostile tribe (3,4)
'tribe' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'one's beaten by hostile' is the wordplay.
'one's beaten' becomes 'drum' (you beat a drum to play it).
'by' is a charade indicator (letters next to each other).
'hostile' becomes 'war' (I can't justify this - if you can you should believe this answer much more).
'drum' after 'war' is 'WAR-DRUM'.
(Other definitions for war drum that I've seen before include "threat of hostilities" , "beaten in battle?" .)
'tribe' is the definition.
I don't know anything about this answer so I can't tell whether this works.
'one's beaten by hostile' is the wordplay.
'one's beaten' becomes 'drum' (you beat a drum to play it).
'by' says to put letters next to each other.
'hostile' becomes 'war' (I can't explain this - if you can you should give a lot more credence to this answer).
'drum' put after 'war' is 'WARDRUM'.
Can you help me to learn more?