A Risk Appetite is the level of risk with which an organisation is prepared to accept or take that is the acceptable level of variation around objectives. The Risk Appetite is to implement and enforce it to relevant business units, while the Risk Tolerance is the maximum level of risk.
Reference definition by ISO 31000: A Risk Appetite is the amount and type of risk that an organization is prepared to pursue, retain or take.
Related Definitions in the Project: The Risk Management; Project Management