metatarsus

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The middle part of the human foot that forms the instep and includes the five bones between the toes and the ankle.
2. n. The corresponding part of the hind foot in quadrupeds or of the foot in birds.

Century Dictionary and Cyclopedia

1. n. The middle segment of the three of which the foot, or third division of the hind limb, consists, considered with special reference to its bony structure. It is the part of the foot between the tarsus and the toes, in man corresponding closely with the instep, and composed of five bones. (See cut under foot.) In a horse it is the part of the hind leg between the hock and the fetlock, and has but one functional bone. In birds it is the part popularly called the shank, and in descriptive ornithology known as the tarsus. In most birds the metatarsus is naked and scaly, and extends from the bases of the toes to the suffrage or first joint above. It usually consists of a single stout bone, representing three metatarsals fused together, and further complicated by the fusion of distal tarsal elements with its proximal end. In birds with four toes the metatarsus includes a small separate bone known as the accessory metatarsal, which is the metatarsal bone of the hallux or hind toe, the metatarsus hallucis.
2. n. In entomology: The first one of the joints of the tarsus, when it is large or otherwise distinguished from the rest, which are then called collectively the dactylus. Also called planta, in which case the other joints are collectively known as the digitus. The peculiarly expanded and bristly metatarsus or planta of bees is known as the scapula.
3. n. With some authors, the hind foot; the entire tarsus of each hind leg; each of the third pair of tarsi. When this nomenclature is used, the tarsus of the middle leg is called mesotarsus and that of the fore leg protarsus.
4. n. The sixth joint of a spider's leg, being the first of the two which form the foot.

Wiktionary

1. n. The part of the foot between the toes and the ankle, especially its five bones.

GNU Webster's 1913

1. n. (Anat.) That part of the skeleton of the hind or lower limb between the tarsus and phalanges; metatarse. It consists, in the human foot, of five bones. See Illustration in Appendix.

WordNet 3.0

1. n. the skeleton of the human foot between the toes and the tarsus; the corresponding part of the foot in birds or of the hind foot in quadrupeds