Even bloodshed can be defeated (4)
I believe the answer is:
lose
'be defeated' is the definition.
(I've seen this in another clue)
'even bloodshed' is the wordplay.
'even' indicates alternate letters (letters in even-numbered positions are used).
The alternating letters of 'bloodshed' are 'LOSE'.
'can' acts as a link.
(Other definitions for lose that I've seen before include "Fail to keep" , "Mislay or be defeated" , "Shake off (a pursuer)" , "Suffer a defeat" , "Don't win" .)