Some military men eventually repelled foe (5)
I believe the answer is:
enemy
'foe' is the definition.
(I know that foe can be written as enemy)
'some military men eventually repelled' is the wordplay.
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'repelled' says the letters should be written backwards.
'ymene' is hidden within 'military men eventually'.
'ymene' written backwards gives 'ENEMY'.
(Other definitions for enemy that I've seen before include "Time" , "Rival" , "one in opposition" , "Opposing force" , "Hostile person, foe" .)