Enterprise

An organization with a defined mission/goal and a defined boundary, using information systems to execute that mission, and with responsibility for managing its own risks and performance. An enterprise may consist of all or some of the following business aspects: acquisition, program management, financial management (e.g., budgets), human resources, security, and information systems, information, and mission management. 
 
See the following under Enterprise for more information:  

NIST SP 800-30 Rev. 1.
NIST SP 800-39.
NIST SP 800-53 Rev. 4.
NIST SP 800-82 Rev. 2  (ANSI/ISA-88.01-1995).