A fibula (/ˈfɪbjʊlə/, plural fibulae /ˈfɪbjʊli/) is an ancient brooch. Technically, the Latin term, fibulae, refers to Roman brooches; however, the term is widely used to refer to brooches from the entire ancient and early medieval world that continue Roman forms. Nevertheless, its use in English is more restricted than in other languages, and in particular post-Roman brooches from the British Isles are just called brooches (for example, the penannular brooches), where in German they would probably be fibulae. Unlike most modern brooches, fibulae were not only decorative; they originally served a practical function: to fasten clothing, such as cloaks. Fibulae replaced straight pins that were used to fasten clothing in the Neolithic period and the Bronze Age. In turn, fibulae were replaced as clothing fasteners by buttons in the Middle Ages. Their descendant, the modern safety pin, remains in use today. In ancient Rome and other places where Latin was used, the same word denoted both a brooch and the fibula bone because a popular form for brooches and the shape of the bone were thought to resemble one another.