'rein in' definitions:

Definition of 'rein in'

From: WordNet
verb
Stop or slow up one's horse or oneself by or as if by pulling the reins; "They reined in in front of the post office" [syn: rein, rein in]
verb
Control and direct with or as if by reins; "rein a horse" [syn: harness, rein in, draw rein, rein]
verb
Stop or check by or as if by a pull at the reins; "He reined in his horses in front of the post office" [syn: rein, rein in]