- A small object fastened to a key chain or key ring and designed to be comfortably grasped.
- Such an object containing a remote-control device, as one that locks and unlocks a car.
(1) A remote control car door opener such as the common "clicker" used with most modern automobiles.
(3) A security token that is attached to a keychain. Ironically, the word is also used as the antithesis of security: "fob off" means to "palm off" a shoddy trinket through deception. See authentication token.