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.

chain.
1. Romanesque moulding carved to resemble a chain.

2. Piece of timber or metal built into a brick wall to increase its stability and cohesion, called chain-bond.

3. Bond course of stone with one or more cramps connecting each pair of stones.

4. Complete circlet formed of a chain, used to prevent a circular work of masonry from spreading, e.g. in the dome of St Paul's Cathedral, London (begun 1675).

5. Chain-tie used to connect the heads of piers, etc., while vaults and arches are constructed.

6. If used to tie in bulging brickwork, an anchor is fixed to the end of the chain or rod, visible on the outside of the wall.

chain1 a series of linked metal rings for fastening or securing something. From the later sense of a jointed measuring line consisting of linked metal rods, chain is also used as a unit of measure for the length of such a measuring line (66 ft).
a chain is no stronger than its weakest link proverbial saying, mid 19th century, often used when identifying a particular point of vulnerability. (In 2000, the popular television game-show The Weakest Link was introduced, turning on the identification and expulsion of the member of a group seen to contribute least; the show's catchphrase is ‘You are the weakest link…goodbye.’)

See also ball and chain.

chain
1. A singly linked linear list.

2. See directed set.

Chain

a series of things linked together into a chain, actually or figuratively. See also catena, cordon, series.

Examples: chain of buckets; of causes, 1829; of charity, 1377; of deductions, 1664; of discourse, 1651; of events; of human beings; of ideas; of islands; of lakes; of mountains; of proof; of reasoning, 1809; of shops or supermarkets; of spangles, 1841; of storms; of succession, 1655; of thought, 1711.