A choker necklace, often known simply as a choker, is a necklace that fits very tightly around the neck. It doesn't drape down to the collarbone or chest, but sits around the throat like a collar. The name choker necklace implies that if it were slightly tighter, it could choke the wearer.
This style of necklace may have developed from the fashion of wearing a ribbon around the neck. During the worst excesses of the French Revolution, young ladies in England and elsewhere took to the fashion of wearing red ribbons around their throats as a symbol of those who had perished at the guillotine -- perhaps the earliest use of ribbons as a gesture of sympathy and solidarity with a class of victims.
The choker necklace should not be confused with a torque or torc; these metal rings are not completely closed, but are a broken circle which can be bent to open. Torques are typified by heavy metal knobs where the circle is broken, often featuring elaborately incised artwork, which lay upon the collarbone.
The choker necklace was also popular in the Roaring Twenties. Chokers are useful for calling attention to a slim and attractive neck, and perhaps for calling attention away from deficits elsewhere.
Today, this style of necklace can form part of a goth look. A black or red choker, with black lace gloves and a plunging neckline, can make one look quite suitable as a vampire's favorite victim. Chokers can also be used to make more forceful fashion statements. Leather chokers studded with metal can imply that one is nobody's victim.