The term 'long bone' refers to a type of bone found in the human body that is longer than it is wide. The four crossword solutions for this term are the TIBIA (5 letters), FIBULA (6 letters), femur (5 letters), and ULNA (4 letters). The TIBIA is the larger of the two bones in the lower leg, while the FIBULA is the smaller bone. The femur is the longest and strongest bone in the human body and is located in the thigh. The ULNA is one of the two bones in the forearm.