Fiery felony (5)
I believe the answer is:
arson
'fiery felony' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for arson that I've seen before include "Iniquitous behaviour" , "Malicious fire-lighting" , "matchplay, say?" , "Pyromaniac's crime" , "A burning crime" .)