instep

noun3

1. •
   The arched part of the top of the foot between the toes and the ankle.

   • The boot pressed uncomfortably against his instep.
   • She kicked the ball with the inside of her instep.
2. •
   A section of any footwear covering that part of the foot.
3. •
   In horses, the hind leg from the ham to the pastern joint.