. (Mach.) A chain in which the alternate links are broad blocks connected by thin side links pivoted to the ends of the blocks, used with sprocket wheels to transmit power, as in a bicycle. [ Webster 1913 Suppl. ]

A watch-guard. [ 1913 Webster ]

n. [ F. chaîne, fr. L. catena. Cf. Catenate. ] 1. A series of links or rings, usually of metal, connected, or fitted into one another, used for various purposes, as of support, of restraint, of ornament, of the exertion and transmission of mechanical power, etc. [ 1913 Webster ]

[ They ] put a chain of gold about his neck. Dan. v. 29. [ 1913 Webster ]

2. That which confines, fetters, or secures, as a chain; a bond; as, the chains of habit. [ 1913 Webster ]

Driven down
To chains of darkness and the undying worm. Milton. [ 1913 Webster ]

3. A series of things linked together; or a series of things connected and following each other in succession; as, a chain of mountains; a chain of events or ideas. [ 1913 Webster ]

4. (Surv.) An instrument which consists of links and is used in measuring land. [ 1913 Webster ]

☞ One commonly in use is Gunter's chain, which consists of one hundred links, each link being seven inches and ninety-two one hundredths in length; making up the total length of rods, or sixty-six, feet; hence, a measure of that length; hence, also, a unit for land measure equal to four rods square, or one tenth of an acre. [ 1913 Webster ]

5. pl. (Naut.) Iron links bolted to the side of a vessel to bold the dead-eyes connected with the shrouds; also, the channels. [ 1913 Webster ]

6. (Weaving) The warp threads of a web. Knight. [ 1913 Webster ]

Chain belt (Mach.), a belt made of a chain; -- used for transmitting power. --
Chain boat, a boat fitted up for recovering lost cables, anchors, etc. --
Chain bolt (a) (Naut.) The bolt at the lower end of the chain plate, which fastens it to the vessel's side. (b) A bolt with a chain attached for drawing it out of position. --
Chain bond. See Chain timber. --
Chain bridge, a bridge supported by chain cables; a suspension bridge. --
Chain cable, a cable made of iron links. --
Chain coral (Zool.), a fossil coral of the genus Halysites, common in the middle and upper Silurian rocks. The tubular corallites are united side by side in groups, looking in an end view like links of a chain. When perfect, the calicles show twelve septa. --
Chain coupling. (a) A shackle for uniting lengths of chain, or connecting a chain with an object. (b) (Railroad) Supplementary coupling together of cars with a chain. --
Chain gang, a gang of convicts chained together. --
Chain hook (Naut.), a hook, used for dragging cables about the deck. --
Chain mail, flexible, defensive armor of hammered metal links wrought into the form of a garment. --
Chain molding (Arch.), a form of molding in imitation of a chain, used in the Normal style. --
Chain pier, a pier suspended by chain. --
Chain pipe (Naut.), an opening in the deck, lined with iron, through which the cable is passed into the lockers or tiers. --
Chain plate (Shipbuilding), one of the iron plates or bands, on a vessel's side, to which the standing rigging is fastened. --
Chain pulley, a pulley with depressions in the periphery of its wheel, or projections from it, made to fit the links of a chain. --
Chain pumps. See in the Vocabulary. --
Chain rule (Arith.), a theorem for solving numerical problems by composition of ratios, or compound proportion, by which, when several ratios of equality are given, the consequent of each being the same as the antecedent of the next, the relation between the first antecedent and the last consequent is discovered. --
Chain shot (Mil.), two cannon balls united by a shot chain, formerly used in naval warfare on account of their destructive effect on a ship's rigging. --
Chain stitch. See in the Vocabulary. --
Chain timber. (Arch.) See Bond timber, under Bond. --
Chain wales. (Naut.) Same as Channels. --
Chain wheel. See in the Vocabulary. --
Closed chain,
Open chain (Chem.), terms applied to the chemical structure of compounds whose rational formulæ are written respectively in the form of a closed ring (see Benzene nucleus, under Benzene), or in an open extended form. --
Endless chain, a chain whose ends have been united by a link. [ 1913 Webster ]

v. t. [ imp. p. p. Chained p. pr. & vb. n. Chaining. ] 1. To fasten, bind, or connect with a chain; to fasten or bind securely, as with a chain; as, to chain a bulldog. [ 1913 Webster ]

Chained behind the hostile car. Prior. [ 1913 Webster ]

2. To keep in slavery; to enslave. [ 1913 Webster ]

And which more blest? who chained his country, say
Or he whose virtue sighed to lose a day? Pope. [ 1913 Webster ]

3. To unite closely and strongly. [ 1913 Webster ]

And in this vow do chain my soul to thine. Shak. [ 1913 Webster ]

4. (Surveying) To measure with the chain. [ 1913 Webster ]

5. To protect by drawing a chain across, as a harbor. [ 1913 Webster ]

adj. bound with chains; as, prisoners chained together to prevent escape.
Syn. -- enchained, in chains(predicate). [ WordNet 1.5 ]

a. Having no chain; not restrained or fettered. “The chainless mind.” Byron. [ 1913 Webster ]

n. A small chain. Sir W. Scott. [ 1913 Webster ]

adj. having a form resembling a chain; as, chainlike clusters of bacteria.
Syn. -- catenulate. [ WordNet 1.5 ]

A pump consisting of an endless chain, running over a drum or wheel by which it is moved, and dipping below the water to be raised. The chain has at intervals disks or lifts which fit the tube through which the ascending part passes and carry the water to the point of discharge. [ 1913 Webster ]

n. metal shackles connected by chains, used to bind hands or legs; as, he was kept two weeks in chains.
Syn. -- iron, irons, chain. [ WordNet 1.5 ]

n. a portable power saw having teeth that are linked to form an endless chain, rotated about two pivot points by a power mechanism, such as an electric motor or a gasoline engine. They are used to efficiently cut trees, logs, or thick branches out of doors.
Syn. -- chain saw. [ WordNet 1.5 ]

1. An ornamental stitch like the links of a chain; -- used in crocheting, sewing, and embroidery. [ 1913 Webster ]

2. (Machine Sewing) A stitch in which the looping of the thread or threads forms a chain on the under side of the work; the loop stitch, as distinguished from the lock stitch. See Stitch. [ 1913 Webster ]

. (Arch.) A tie consisting of a series of connected iron bars or rods. [ Webster 1913 Suppl. ]

1. A chain pulley, or sprocket wheel. [ 1913 Webster ]

2. An inversion of the chain pump, by which it becomes a motor driven by water. [ 1913 Webster ]

n. Work looped or linked after the manner of a chain; chain stitch work. [ 1913 Webster ]

adj. (Chem.) having atoms linked by bonds which form a ring.
Syn. -- closed-ring. [ WordNet 1.5 ]

. (Logging) A form of tackle for loading a log sideways on a sled, skidway, etc. [ Webster 1913 Suppl. ]

a. Freed from restraint; unrestrained. [ Archaic ] E. A. Poe. [ 1913 Webster ]

v. t. [ F. enchaîner; pref. en- (L. in) chaîne chain. See Chain, and cf. Incatenation. ] 1. To bind with a chain; to hold in chains. [ 1913 Webster ]

2. To hold fast; to confine; as, to enchain attention. [ 1913 Webster ]

3. To link together; to connect. Howell. [ 1913 Webster ]

n. [ Cf. F. enchaînement. ] The act of enchaining, or state of being enchained. [ 1913 Webster ]

(Surveying) The chain ordinarily used in measuring land. See Chain, n., 4, and Gunter's scale. [ 1913 Webster ]

n. A chain or tie rod, in a boat or barge, to prevent the vessel from hogging. [ 1913 Webster ]

v. t. [ imp. & p. p. Interchained p. pr. & vb. n. Interchaining. ] To link together; to unite closely or firmly, as by a chain. [ 1913 Webster ]

Two bosoms interchained with an oath. Shak. [ 1913 Webster ]

n. [ after A. A. Markov, Russian mathematician, b. 1856, d. 1922. ] (Statistics) A random process (Markov process) in which the probabilities of discrete states in a series depend only on the properties of the immediately preceding state or the next preceeding state, independent of the path by which the preceding state was reached. It differs from the more general Markov process in that the states of a Markov chain are discrete rather than continuous. Certain physical processes, such as diffusion of a molecule in a fluid, are modelled as a Markov chain. See also random walk. [ Also spelled Markoff chain. ] [ PJC ]

adj. (Chemistry) not cyclic; having no rings of atoms within the molecular structure; having an open chain structure. Opposite of cyclic. [ Narrower terms: aliphatic ]
Syn. -- acyclic. [ WordNet 1.5 ]

. (a) (Railroads) A normally slack chain for preventing excessive movement between a truck and a car body in sluing. (b) An auxiliary watch chain, secured to the clothes, usually out of sight, to prevent stealing of the watch. (c) A chain of sheet metal links with an elongated hole through each broad end, made up by doubling the first link on itself, slipping the next link through and doubling, and so on. [ Webster 1913 Suppl. ]

Safety arch (Arch.), a discharging arch. See under Discharge, v. t. --
Safety belt, a belt made of some buoyant material, or which is capable of being inflated, so as to enable a person to float in water; a life preserver. --
Safety buoy, a buoy to enable a person to float in water; a safety belt. --
Safety cage (Mach.), a cage for an elevator or mine lift, having appliances to prevent it from dropping if the lifting rope should break. --
Safety lamp. (Mining) See under Lamp. --
Safety match, a match which can be ignited only on a surface specially prepared for the purpose. --
Safety pin, a pin made in the form of a clasp, with a guard covering its point so that it will not prick the wearer. --
Safety plug. See Fusible plug, under Fusible. --
Safety switch. See Switch. --
Safety touchdown (Football), the act or result of a player's touching to the ground behind his own goal line a ball which received its last impulse from a man on his own side; -- distinguished from touchback. See Touchdown. Same as safety --
Safety tube (Chem.), a tube to prevent explosion, or to control delivery of gases by an automatic valvular connection with the outer air; especially, a bent funnel tube with bulbs for adding those reagents which produce unpleasant fumes or violent effervescence. --
Safety valve, a valve which is held shut by a spring or weight and opens automatically to permit the escape of steam, or confined gas, water, etc., from a boiler, or other vessel, when the pressure becomes too great for safety; also, sometimes, a similar valve opening inward to admit air to a vessel in which the pressure is less than that of the atmosphere, to prevent collapse. [ 1913 Webster ]

(Naut.) A chain sheet cable. [ 1913 Webster ]

. (Physiol. Chem.) A theory proposed by P. Ehrlich as a chemical explanation of immunity phenomena. In brief outline it is as follows: Animal cells and bacteria are complex aggregations of molecules, which are themselves complex. Complex molecules react with one another through certain of their side chains, but only when these side chains have a definite correspondence in structure (this accounts for the specific action of antitoxins). [ Webster 1913 Suppl. ]

n. (Naut.) A chain for slinging the lower yards, in time of action, to prevent their falling, if the ropes by which they are hung are shot away. [ 1913 Webster ]

v. t. [ 1st pref. un- + chain. ] To free from chains or slavery; to let loose. Prior. [ 1913 Webster ]