The malicious burning of property (5)
I believe the answer is:
arson
'the malicious burning of property' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for arson that I've seen before include "major crime" , "Malicious burning to destroy property" , "Incendiary crime" , "Felonious burning of property" , "Pyromaniac's crime" .)