rule
noun
1.
a principle or condition that customarily governs behavior
2.
something regarded as a normative example
4.
(linguistics) a rule describing (or prescribing) a linguistic practice
5.
7.
8.
directions that define the way a game or sport is to be conducted
9.
any one of a systematic body of regulations defining the way of life of members of a religious order
10.
a rule or law concerning a natural phenomenon or the function of a complex system
11.
(mathematics) a standard procedure for solving a class of mathematical problems