Head off burning rage (3)
I believe the answer is:
ire
'rage' is the definition.
(I've seen this before)
'head off burning' is the wordplay.
'head off' means to remove the first letter.
'burning' becomes 'fire' (fire is a kind of burning).
'fire' with its first letter removed is 'IRE'.
(Other definitions for ire that I've seen before include "Hot temper" , "'Anger, wrath (3)'" , "Choler" , "Strong feeling" , "Anger, rage" .)