1. To put a bridle on.
2. To respond to the reins, said of horses.

ETYM Old Eng. bridel, AS. bridel; akin to Old High Germ. britil, brittil, Dutch breidel, and possibly to Eng. braid. Related to Bridoon.
(Homonym: bridal).
1. Headgear for a horse; includes a headstall and bit and reins to give the rider or driver control.
2. The act of restraining power or action or limiting excess; SYN. check, curb.