rein
noun [ C usually plural ] uk/reɪn/ us/reɪn/
（尤指皮质的）缰绳
a long, thin piece of material, especially leather, that helps you to control and direct a horse
You pull on both reins to stop or slow a horse, but only the left rein to turn left. 拉两边的缰绳来让马停住或放慢速度，但是要想左转时，只需拉左边的缰绳。
UK（领幼儿走路时防止其走失的）安全绳套，保护带
a strap that is put around a small child's body or wrist and held at the other end by an adult so that the adult can stop the child running away
I always put my son on reins when we go shopping. 我们带儿子去购物时，总是用安全带牵着他。
Idioms
free reinidiom （言行或情感的）自由，自主，无约束
the freedom to do, say, or feel what you want
The young film-makers were given free rein to experiment with new themes and techniques. 年轻的电影制片者们对新主题和新技巧可以自由尝试。
He deliberately gave his emotions free rein as he played the sonata. 演奏这首奏鸣曲时，他刻意使自己的感情尽情奔放。
keep a tight rein on someone/somethingidiom (also keep someone/something on a tight rein) 对…严加约束；对…严加控制
to have a lot of control over someone or something
My father always kept us on a tight rein. 我父亲对我们总是严加管教。
take over/up the reinsidiom 控制；接管（某东西，尤指某机构或国家）
to take control of something, especially an organization or a country
He took up the reins of government immediately after the coup. 在那次政变之后，他立即控制了政府。
Synonyms: check (LIMIT)constraintcontrol (POWER)curb (CONTROL)curtailmentlimit limitationrestraintrestriction