HackerVoca

register : enroll, list, record, catalogue
regret : deplore, lament
regular : uniform, even, systematic, formal, orderly
regulate : control, direct, adjust, arrange
regulation : rule, order, law
rehearse : recite, practice, drill, train
reign1 / noun [countable]

1 the period of time during which someone is king or queen: the reign of Queen Victoria

2 a period during which something is the most powerful or most important feature of a place: the reign of Stalinism in Russia | reign of terror (=when a government kills many of its political opponents)