The ability to anticipate, withstand, recover from, and adapt to adverse conditions, stresses, attacks, or compromises on systems that use or are enabled by cyber resources.
Source(s):
NIST SP 800-172 from NIST SP 800-160 Vol. 2
NIST SP 800-160 Vol. 2 [Superseded]

  The ability to anticipate, withstand, recover from, and adapt to adverse conditions, stresses, attacks, or compromises on systems that use or are enabled by cyber resources. Cyber resiliency is intended to enable mission or business objectives that depend on cyber resources to be achieved in a contested cyber environment.
Source(s):
NIST SP 800-160 Vol. 2 Rev. 1
NIST SP 800-172A from NIST SP 800-160 Vol. 2 Rev. 1