A keychain or key chain's a small chain, usually made from metal or plastic, that connects a small item to a keyring. The length of a keychain allows an item to be used more easily than if connected directly to a keyring. Some keychains allow one or both ends the ability to rotate, keeping the keychain from becoming twisted, while the item's being used. A keychain can also be a connecting link between a keyring (a.k.a. "split ring") and the belt of an individual. It's usually employed by person… (More on Keychain)