arson n[Anglo-French arsoun , alteration of Old French arsin , literally, conflagration, from ars , past participle of ardre to burn]
: the act or crime of willfully, wrongfully, and unjustifiably setting property on fire often for the purpose of committing fraud (as on an insurance company)
Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.