Bloody end for poor newspaper boss (3)
I believe the answer is:
red
'bloody' is the definition.
'end for poor newspaper boss' is the wordplay.
'end for' says to take the final letters.
'newspaper boss' becomes 'ed' (short for editor).
The last letter of 'poor' is 'r'.
'r'+'ed'='RED'
(Other definitions for red that I've seen before include "Colour of garnets" , "A colourful communist" , "Crimson" , "lefty" , "Colour of communism" .)