Bb: Bridle

Noun

1. headgear for controlling a horse, consisting of straps and a bit and reins

2. something that curbs or restrains

Verb

[-dling, -dled]

1. to show anger or indignation: he bridled at the shortness of her tone

2. to put a bridle on (a horse)

3. to restrain; curb [Old English brigdels]

I had of course long been used to a halter and a headstall, and to be led about in the fields and lanes quietly, but now I was to have a bit and bridle; my master gave me some oats as usual, and after a good deal of coaxing he got the bit into my mouth, and the bridle fixed, but it was a nasty thing...
Black Beauty by Anna Sewall