bone of the tarsus that forms the heel
Tarsus (skeleton) The talus bone or ankle bone is connected superiorly to the two bones of the lower leg, the tibia and fibula, to form the ankle joint or talocrural joint; inferiorly, at the subtalar joint, to the calcaneus or heel bone. Together, the talus and calcaneus form the hindfoot.[1]
Achilles tendon The Achilles tendon or heel cord, also known as the calcaneal tendon (Latin: Tendo calcaneus), is a tendon of the back of the leg, and the thickest in the human body. It serves to attach the plantaris, gastrocnemius (calf) and soleus muscles to the calcaneus (heel) bone. These muscles, acting via the tendon, cause plantar flexion of the foot at the ankle, and (except soleus) flexion at the knee.