rule

noun [C usually plural] (INSTRUCTION)

/ruːl/

Definition

1. Definition

2. Practise

B1 an accepted principle or instruction that states the way things are or should be done, and tells you what you are allowed or are not allowed to do: A referee must know all the rules of the game. The first/most important rule in life is always to appear confident. Before you start your own business you should be familiar with the government's rules and regulations. You must follow/obey/observe the rules. You must not break the rules. In special cases the manager will bend/stretch the rules (= allow the rules to be broken). You can trust Ruth because she always plays (it) by/goes by/does things by the rules (= follows instructions, standards, or rules). [+ to infinitive] It's against the rules (of/in boxing) to hit below the belt. [+ that] It's a club rule that new members must sing a song.Rules and laws

(Definition of rule noun (INSTRUCTION) from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)