Legislation made by a person or body other than the Sovereign in Parliament, by virtue of powers conferred either to statute or by legislation which is itself made under statutory powers. It is also called subordinate legislation.
It is obvious that such an authority is ancillary to legislation, and without it an attempt to provide for varying details and machinery to carry them out might be oppressive, or absolutely fail. There are abundance of precedents for this legislation, entrusting a limited a discretionary authority to others, and many illustrations of its necessity and convenience. ….. [Hodge v. Queen LR 9 A.C. 117]