no obj.
1- hold royal office; rule as king or queen为王, 为君; 统治：
Queen Elizabeth reigns over the UK
伊丽莎白女王是联合王国的君主
figurative 〈喻〉the Nashville sound will reign supreme once again.
纳什维尔的乡村音乐风格将再度称霸。
1.1
- usu. as adj. reigning(of a sports player or team) currently hold a particular title（运动员或运动队）持有当前某荣誉称号（的）：
the reigning world champion.
本届世界冠军。
1.2
- (of a quality or condition) prevail; predominate盛行; 主宰：
confusion reigned.
混乱主宰着整个局面。
1
- the period during which a sovereign rules统治期, （君主）在位期：
the original chapel was built in the reign of Charles I.
原有的礼拜堂建于查尔斯一世当政时期。
1.1
- the period during which a sports player or team holds a specified title（运动员, 运动队）持有指明荣誉头衔的时期。
USAGE
The correct idiomatic phrase is a free rein, not a free reign; see usage at REIN.
词源
Middle English: from Old French reignier 'to reign', reigne 'kingdom', from Latin regnum, related to rex, reg- 'king'.