n. 马缰绳, 控制

vt. 控制

[ noun ]
a rein designed to keep the horse's head in the desired position
<noun.artifact>

Checkrein \Check"rein`\, n.
1. A short rein looped over the check hook to prevent a horse
from lowering his head; -- called also a {bearing rein}.

2. A branch rein connecting the driving rein of one horse of
a span or pair with the bit of the other horse.