instep

 
Pronunciation: /ˈɪnstɛp/

noun

  • the part of a person’s foot between the ball and the ankle.
  • the part of a shoe which fits over or under the instep: the shoes are comfortable because they have a moulded instep
  • a thing shaped like the inner arch of a foot.

Origin:

late Middle English: of unknown origin; compare with West Frisian ynstap 'opening in a shoe for insertion of the foot'