A gewgaw is a little ornament or piece of jewelry. Gewgaws are cheap and don't have any purpose besides decoration.
Gewgaws, which go on clothing or are worn as jewelry, are small and ornamental little bits of decoration. They’re not valuable or useful. A diamond would never be considered a gewgaw, because it's so precious. Gewgaws are good for brightening up an outfit. Pieces of jewelry, especially when they're flashy and cheap, can be called gewgaws. The silly sound of this word is a reminder that gewgaws are insubstantial. A gewgaw can also be called a bauble, novelty, or trinket.