●keep a tight ˈrein on sb/sth ( keep sb/sth on a tight ˈleash) control sb/sth very carefully; give sb/sth very little freedom对…严加约束；牢牢驾驭◆The company must keep a tight rein on spending.公司必须严格控制支出。◆She keeps her children on a tight leash to make sure they don’t get into trouble.她严加管教自己的孩子，以保证他们不会惹麻烦。OPPgive/allow sb/sth free/full reinNOTE A leash is used to hold and control a dog, and a rein is used to control a horse. * leash 指拴狗用的皮带，rein 则指马的缰绳。