pastern

noun

1. The part of a horse's leg between the fetlock joint and the hoof.

   “It was quite impossible to ride over the deeply-ploughed field; the earth bore only where there was still a little ice, in the thawed furrows the horse's legs sank in above its pasterns.”

   “Below me, somewhere in the horse-lines, stood Cockbird, picketed to a peg in the ground by a rope which was already giving him a sore pastern.”

2. (obsolete)A shackle for horses while pasturing.
3. (obsolete)A patten.

   “Upright he walks, on pasterns firm and straight; His motions easy; prancing in his gait So straight she walk'd, and on her pasterns high.”