Wednesbury unreasonable

Etymology
. Wednesbury refers to the case of, in which the refused to quash a decision by the Wednesbury Corporation to ban children under 15 from entering cinemas on Sundays, and laid down in what cases courts could quash unreasonable administrative decisions.

Adjective

 * 1)  In judicial reviews of administrative decisions: being unreasonable to the extent that no reasonable person or authority would make such a decision.