rule
/ɹuːl/
A regulation, law, guideline.
All participants must adhere to the rules.
A ruler; device for measuring, a straightedge, a measure.
A straight line (continuous mark, as made by a pen or the like), especially one lying across a paper as a guide for writing.
A regulating principle.
The act of ruling; administration of law; government; empire; authority; control.
A normal condition or state of affairs.
As a rule, our senior editors are serious-minded.
Conduct; behaviour.
An order regulating the practice of the courts, or an order made between parties to an action or a suit.
A determinate method prescribed for performing any operation and producing a certain result.
a rule for extracting the cube root
A thin plate of brass or other metal, of the same height as the type, and used for printing lines, as between columns on the same page, or in tabular work.