rein /rein/ I. n. ［c］缰绳： make a horse go more slowly or stop by pulling on its reins拉缰绳可以使马走慢一些或让它停下来 give free rein to sb(to do sth.)让某人自由（干某事）：The school gives teachers free rein to try out new teaching methods. 学校给予教师充分试验新的教学方法的自由。keep a tight rein on sb. or keep sb. on a tight rein控制某人：My father always kept us on a tight rein. 父亲总是对我们控制很紧。‖II. v. 用于短语动词 rein in控制：The federal government is attempting to rein in health care costs.联邦政府正努力控制医疗费用的增加。