What is the meaning of Necklace?

An article of jewelry that is worn around the neck, most often made of a string of precious metal, pearls, gems, beads or shells, and sometimes having a pendant attached.

Anything resembling a necklace in shape.

A device used in necklacing (an informal execution); a rubber tyre that is filled with petrol. It is placed around the victim's chest and arms, and set on fire.

To informally execute by necklacing; by setting on fire a petrol-filled rubber tyre which has been put around the bound victim's neck.

Source: wiktionary.org