Open English Wordnet
Nouns
(n)rule, regulationa principle or condition that customarily governs behavior“it was his rule to take a walk before breakfast”, “short haircuts were the regulation”
(n)regulation(embryology) the ability of an early embryo to continue normal development after its structure has been somehow damaged or altered
(n)regulation, regulatingthe act of controlling or directing according to rule“fiscal regulations are in the hands of politicians”