Fibula meant a brooch or clasp in Latin — the kind of safety-pin-like fastener used throughout the ancient world to hold garments together. Early modern anatomists borrowed the word for the slender bone running alongside the tibia in the lower leg because the two bones together suggested the shape of such a clasp: two parallel prongs joined at one end, like the arms of a brooch.
The Latin word likely derives from figere, meaning to fix or to fasten. This same root produced English fix, affix, prefix, suffix, and crucify (literally to fasten to a cross). The fibula brooch was so named because it was the thing that fastens. The anatomical bone inherited the name through visual resemblance rather than function.
Archaeological fibulae are among the most studied artifact types in classical and prehistoric archaeology. Because brooch styles changed frequently and varied by region, a specific fibula design can date a burial or habitation layer with considerable precision. Archaeologists have created detailed typologies covering thousands of variants from the Bronze Age through the medieval period. The fibula brooch is to the archaeologist what the index fossil
Anatomically, the fibula is the thinner and more lateral of the two lower leg bones. Unlike the tibia, it bears very little body weight. Its primary functions are providing attachment points for muscles and stabilizing the ankle joint. The lateral malleolus — the bony bump on the outside of the ankle — is the lower end of the fibula.
Despite its modest role in weight-bearing, the fibula has a modern medical application. Surgeons sometimes harvest sections of fibula for bone grafts elsewhere in the body, particularly in jaw reconstruction. The fibula regenerates reasonably well and its removal does not seriously impair leg function, making it a useful source of transplantable bone.