bridle (n.) Look up bridle at Dictionary.com
Old English bridel "bridle, rein, curb, restraint," related to bregdan "move quickly," from Proto-Germanic *bregdilaz (see braid (v.)).
bridle (v.) Look up bridle at Dictionary.com
"to control, dominate," c. 1200, from Old English bridlian "to fit with a bridle," from bridel (see bridle (n.)). Meaning "to throw up the head" (as a horse does when reined in) is from mid-15c. Related: Bridled; bridling.