Source : Webster's Revised Unabridged Dictionary (1913)

Hackamore \Hack"a*more\, n. [Cf. Sp. jaquima headstall of a
   halter.]
   A halter consisting of a long leather or rope strap and
   headstall, -- used for leading or tieing a pack animal.
   [Western U.S.]

Source : WordNet®

hackamore
     n : rope or canvas headgear for a horse, with a rope for leading
         [syn: {halter}]