Access control based on user roles (i.e., a collection of access authorizations a user receives based on an explicit or implicit assumption of a given role). Role permissions may be inherited through a role hierarchy and typically reflect the permissions needed to perform defined functions within an organization. A given role may apply to a single individual or to several individuals.
Sources:
CNSSI 4009-2015

  A model for controlling access to resources where permitted actions on resources are identified with roles rather than with individual subject identities.
Sources:
NIST SP 800-95 under Role Based Access Control (RBAC) from OASIS XACML Profile for Role Based Access Control (RBAC)

  mapped to job function, assumes that a person will take on different roles, overtime, within an organization and different responsibilities in relation to IT systems.
Sources:
NIST SP 800-16 under Role-Based

  Access control based on user roles (i.e., a collection of access authorizations that a user receives based on an explicit or implicit assumption of a given role). Role permissions may be inherited through a role hierarchy and typically reflect the permissions needed to perform defined functions within an organization. A given role may apply to a single individual or to several individuals.
Sources:
NIST SP 800-53 Rev. 5 under role-based access control