A more thorough explanation:

Definition: Piacle is an old-fashioned word that means a very serious crime.

Examples:

• Committing murder was considered a piacle in medieval times.
• Stealing from the church was seen as a piacle and punished severely.

The examples show that piacle refers to a crime that is considered very serious and often has severe consequences. In medieval times, crimes such as murder and theft from the church were seen as piacles and punished harshly.