A jacket, almost on fire (6)
I believe the answer is:
ablaze
'on fire' is the definition.
(synonyms)
'a jacket almost' is the wordplay.
I cannot quite understand how this works, but
'a' is found in the answer.
The remaining letters 'blaze' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for ablaze that I've seen before include "Well-lit" , "burnt" , "Fiery" , "Burning fiercely" , "filled with anger" .)