Arch

Technically the foot has at least four arches, although there are two major arches, the longitudinal arch, which extends along the length of the foot on the medial or inner side, under the instep from the joint to the heel; and the metatarsal arch, formed by the natural arching of the metatarsals at the joints of the foot.

The curved inside part of the foot, where the bones form a bridge from heel to ball.

The curved shape of the inner or medial side of the foot formed by the span between the heel and the joint 

The foot has a natural arch on the inside, formed between the calaneum base and the beginning of the metatarsal joint. This is known as the longitudinal arch, and is usually the one referred to. There is another arch, the metatarsal arch, formed by the natural arching of the base of the metatarsals.

The upward curve at the side of the foot. Sometimes known as the longitudinal arch. Some authorities claim four different arches for the foot.

The bow-like upward curve on the bottom of your midfoot

The part of plantar that does not touch the ground. Most commonly used of metatarsal arch.

Ankle shoe

An item of footwear, and a subset of "boot", where the top is approximately on the ankle joint, or extends just above the ankle.

Shoe with uppers that reach just to or over the ankle

Aglet

A binding around the end of a lace to protect it, reinforce it and help thread it through holes.  Although they are not commonly found, medieval boot and shoe aglets seem to have been coiled brass wire, while those for clothing were wrapped metal sheets.  In some forms of medieval boot and shoe lacing only a single end might need an aglet, while the other end was just knotted or stitched inside the shoe or boot.  Aglets were used on some leather laces, and if they were used on cloth laces these have not survived