■ noun
1》 a regulation or principle governing conduct or procedure within a particular area of activity.
↘a code of practice and discipline for a religious community: the Rule of St Benedict.
2》 control or government: an end to British ~.
3》 ( the ~ ) the normal or customary state of things.
4》 a straight strip of rigid material used for measuring; a ~r.
5》 a thin printed line or dash.
■ verb
1》 exercise ultimate power over (a people or nation).
↘exert a powerful and restricting influence on.
↘ informal be very good or the best.
2》 pronounce authoritatively and legally to be the case.
3》 [often as adjective ~d ] make parallel lines on (paper).
4》 ( ~ something out/in ) exclude (or include) something as a possibility.
Phrases
as a ~ usually, but not always.
~ of law the restriction of power by well-defined and established laws.
~ of the road a custom or law regulating the direction in which two vehicles should move to pass one another on meeting to avoid collision.
~ of thumb a broadly accurate guide or principle, based on practice rather than theory.
~ the roost be in complete control.
Derivatives
~less adjective
Origin
ME: from OFr. reule (n.), reuler (v.), from late L. regulare , from L. regula 'straight stick'.