The term 'Knee Neighbor' refers to the two bones that are located on either side of the knee joint. The two bones are the CALF (4 letters) and the SHIN (4 letters). The CALF bone is located at the back of the lower leg and is the largest bone in the leg. The SHIN bone is located at the front of the lower leg and is the longest bone in the body. Together, these two bones form the knee joint, which allows for movement of the leg.