The femur is another name for the thigh bone, according to InnerBody. The Latin name for the femur is the os femoris, as stated by Anatomy Atlases.
The two femurs are the longest and strongest bones in the human body, according to InnerBody. The femurs support the full weight of the body during upright activities, such as running and walking. The upper end of each femur forms a ball that fits into a socket of the hip bone. At the lower end of each femur is the knee joint, at which the femur meets the tibia, or lower leg bone.