1.an authoritative rule
2.a principle or condition that customarily governs behavior;
it was his rule to take a walk before breakfast
3.the state of being controlled or governed
4.(embryology) the ability of an early embryo to continue normal development after its structure has been somehow damaged or altered
5.the act of bringing to uniformity; making regular
6.the act of controlling or directing according to rule;
fiscal regulations are in the hands of politicians
7.prescribed by or according to regulation;
regulation army equipment