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rein someone or something in
to bring someone or something under control; to slow down someone or something. Fred is getting out of hand. The boss undertook to rein him in a bit. The boss is trying to rein in Jane's enthusiasm.
rein in somebody/somethingalso rein somebody/something in
to control someone or something We should rein in our spending, balance our budget, and stop borrowing. Critics say they have run the company as a personal kingdom, pocketing the profits and ignoring anyone who tried to rein them in.
1. To restrain or control something or someone: The coalition tried to rein in its more militant members. I reined my anger in and refused to fight.
2. To make a horse move more slowly or stop by pulling back on reins: Rein in your horse while this truck goes by. The horses wanted to break free, but the rancher reined them in.