Legbone refers to the longest bone in the human body, the femur. However, there are numerous other synonyms that can describe this important bone. Some of them include thigh bone, shank bone or tibia, and fibula. Other synonyms used to describe the lower limb of the human body include the tarsus, metatarsus, patella, and phalanges. Some animals have different types of legbones. For example, a horse's legbones are described as cannon bones, pastern bones, and fetlock bones. In summary, whether you refer to it as a legbone, femur, thigh bone, or shank bone, it remains one of the most crucial bones in the human and animal anatomy.