Bloody half of literary device (4)
I believe the answer is:
gory
'bloody' is the definition.
(similar in meaning)
'half of literary device' is the wordplay.
'half of' means to take half the letters.
'literary device' becomes 'allegory' (I've seen this before).
'allegory' with half the letters taken is 'GORY'.
(Other definitions for gory that I've seen before include "Involving much blood" , "Maybe gruesome" , "Bloodstained" , "Covered in blood" , "Steeped in blood" .)