The methods and processes used by an enterprise to manage risks to its mission and to establish the trust necessary for the enterprise to support shared missions. It involves the identification of mission dependencies on enterprise capabilities, the identification and prioritization of risks due to defined threats, the implementation of countermeasures to provide both a static risk posture and an effective dynamic response to active threats; and it assesses enterprise performance against threats and adjusts countermeasures as necessary.
Sources:
CNSSI 4009-2015 under enterprise risk management

  An effective agency-wide approach to addressing the full spectrum of the organization’s significant risks by understanding the combined impact of risks as an interrelated portfolio, rather than addressing risks only within silos.
Sources:
NIST SP 800-221 under Enterprise Risk Management from OMB Circular A-123
NISTIR 8286 under Enterprise Risk Management from OMB Circular A-11

  The culture, capabilities, and practices that organizations integrate with strategy-setting and apply when they carry out that strategy, with a purpose of managing risk in creating, preserving, and realizing value.
Sources:
NISTIR 8286 under Enterprise Risk Management from COSO Enterprise Risk Management