instep

The instep is the arched top part of the human foot, between the toes and the ankle. It is the place that can feel sore if a shoe presses too hard across the top of your foot. The word is also used for the part of a shoe, boot, or sock that covers this area. In horse anatomy, it can also mean the hind metatarsus, the part of the hind leg between the hock and the fetlock.

The word "instep" is most often used for the arched top part of the human foot, the area between the toes and the ankle. It matters in everyday life more than people sometimes notice: if a shoe is too tight across this part of the foot, walking can quickly become uncomfortable. That is why people talk about having a high instep or needing shoes with more room across the top. The word can also be used for the matching part of a shoe, boot, or sock, meaning the section that lies over and covers that part of the foot.

There is also a more specialized use in horse anatomy. In that sense, "instep" refers to the hind metatarsus, the part of the hind leg between the hock and the fetlock. This is not the meaning most learners will meet first, but it does appear in older dictionaries and technical descriptions. It is also worth keeping separate from the phrase "in step." "In step" means moving together or being in agreement, while "instep" names a physical part of the body, or the part of a shoe or sock that covers it.