rein in

(verb) stop or slow up one's horse or oneself by or as if by pulling the reins. Synonyms: rein, rein in. Example: "They reined in in front of the post office."

(verb) control and direct with or as if by reins. Synonyms: harness, rein in, draw rein, rein. Example: "Rein a horse."

(verb) stop or check by or as if by a pull at the reins. Synonyms: rein, rein in. Example: "He reined in his horses in front of the post office."