chain / chān/ • n. 1. a connected flexible series of metal links used for fastening or securing objects and pulling or supporting loads. ∎  (chains) such a series of links, or a set of them, used to confine a prisoner: kept in chains. ∎  such a series of links worn as a decoration; a necklace. ∎ chiefly Brit. such a series of links worn as a badge of office. ∎  (chains) fig. a force or factor that binds or restricts someone: the chains of illness. ∎  (chains) short for snow chains. 2. a sequence of items of the same type forming a line: he kept the chain of buckets supplied with water. ∎  a sequence or series of connected elements: a chain of events. ∎  a group of establishments, such as hotels, stores, or restaurants, owned by the same company: the nation's largest hotel chain. ∎  a range of mountains. ∎  a part of a molecule consisting of a number of atoms (typically carbon) bonded together in a linear sequence. ∎  a figure in a quadrille or similar dance, in which dancers meet and pass each other in a continuous sequence. 3. a jointed measuring line consisting of linked metal rods. ∎  the length of such a measuring line (66 ft.). ∎  Football a measuring chain of ten yards, used in the determination of first downs. 4. (chains) a structure of planks projecting horizontally from a sailing ship's sides abreast of the masts, used to widen the basis for the shrouds. [ORIGIN: formed earlier of iron plates.]• v. [tr.] fasten or secure with a chain: she chained her bicycle to the railing. ∎  confine with a chain: he had been chained up | fig. as an actuary you will not be chained to a desk.