Headstall

Head′stallˊ

(-sta̤lˊ)

,

Noun.

That part of a bridle or halter which encompasses the head.

Shak.

,

Noun.

hed'stall. That part of a bridle which encompasses the head.

headstall ‎(plural headstalls)

The part of a bridle that fits over a horse's head and supports other elements. [from 14th c.]
- 1596, Edmund Spenser, The Faerie Queene, V.3:
  Another, that would seeme to have more wit, / Him by the bright embrodered hed-stall tooke […].
- 1989, Keith Bosley, translating Elias Lönnrot, The Kalevala, XIX:
  Then the smith Ilmarinen / the everlasting craftsman / out of steel formed a bridle / forged a headstall [transl. päitset] of iron […].
(obsolete) A phorbeia. [18th-19th c.]

part of the bridle that fits over the horse's head

Baranowski, Zdzislaw, "The International Horseman's Dictionary", Pitman Publishing, New York, 1955

Stratton, Charles, "The International Horseman's Dictionary", Hamlyn Publishing, Melbourne, 1975

Summerhayes, R.S., "Encyclopedia for Horsemen", Frederick Warne & Co., London and New York, 1966