What term describes the act of setting an intentional fire to a structure?

The act of setting an intentional fire to a structure is best described by the term arson. Arson involves a willful act of starting a fire, typically with the intent to cause damage or destruction to property. This criminal act is often motivated by various factors, including financial gain, vandalism, or even to conceal other crimes.

Understanding the implications of arson is critical, particularly in the fields of law enforcement and fire investigation, as it is treated as a severe offense due to the potential risks to life and property. Other terms such as negligence and fire hazard do not encompass the intentional aspect of starting a fire, while malice refers more broadly to the intention behind harmful actions but is not specific to the act of setting fires. Thus, arson is the precise legal term that aligns with the definition provided in the question.