The term 'necklace holder' can be summarized as an item used to secure a necklace around the neck. The crossword solution for this term is 'CLASP, ' which is a device used to fasten two parts of a necklace together. A CLASP is typically made of metal and is often decorated with jewels or other decorations. It is an essential part of any necklace, as it allows the wearer to easily put on and take off the necklace.