The principle that a security architecture should be designed so that each entity is granted the minimum system resources and authorizations that the entity needs to perform its function.
NIST SP 800-171 Rev. 1
NIST SP 800-12 Rev. 1 under Least Privilege
A security principle that restricts the access privileges of authorized personnel (e.g., program execution privileges, file modification privileges) to the minimum necessary to perform their jobs.
NIST SP 800-57 Part 2 under Least privilege