Was furious with a bad newspaper editor (5)
I believe the answer is:
raged
'was furious' is the definition.
(I've seen this in another clue)
'with a bad newspaper editor' is the wordplay.
'with' is a charade indicator (letters next to each other).
'a bad newspaper' becomes 'rag' (I've seen this in another clue).
'editor' becomes 'ed' (abbreviation).
'rag' put next to 'ed' is 'RAGED'.
(Other definitions for raged that I've seen before include "Behaved violently" , "seethed" , "Spoke violently" , "Felt intense anger" , "Showed violent anger" .)