Definition: a type of open-frame clasp, through which a chain or ribbon can be passed; the front is often elaborate while the back has one or two vertical bars, similar to a buckle but without the central tongue; developed as a form of jewelry, used to fasten and - as it grew more ornate - to adorn bracelets, necklaces and belts, in the mid-18th century; in Britain, can also refer to a hair ornament with a central bar and spring, known as the barrette
Example: The 1799 emerald and ruby slide looked especially effective when a black velvet ribbon was threaded through it.