Firework beginning to go off, creating fury (5)
I believe the answer is:
anger
'fury' is the definition.
(I've seen this before)
'firework beginning to go off' is the wordplay.
'firework' becomes 'banger' (banger is a kind of firework).
'beginning to go off' means to remove the first letter (the first letter is taken off the word).
'banger' with its initial letter removed is 'ANGER'.
'creating' is the link.
(Other definitions for anger that I've seen before include "Feeling of vexation" , "Great annoyance" , "Spleen" , "Emotion" , "Hot displeasure; enrage" .)