hackamore

noun

1. a simple looped bridle, by means of which controlling pressure is exerted on the nose of a horse, used chiefly in breaking colts.
2. Western U.S. any of several forms of halter used especially for breaking horses.

noun

1. US and NZ a rope or rawhide halter used for unbroken foals

n.

halter for breaking horses, 1850, American English, of uncertain origin. OED and Klein suggests a corruption of Spanish jaquima (earlier xaquima) “halter, headstall of a horse,” which Klein suggests is from Arabic shakimah “bit of a bridle, curb, restraint.”