A cumulative effect produced when one event sets off a chain of similar events: the domino effect of increasing the speed limit in one of several contiguous states.
[From the fact that a row of dominoes stood on end will fall in succession if the first one is knocked over.]
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The domino effect is a chain reaction that occurs when a small change causes a similar change nearby, which then will cause another similar change, and so on in linear sequence. The term is best known as a mechanical effect, and is used as an analogy to a falling row of dominoes. It typically refers to a linked sequence of events where the time between successive events is relatively small. It can be used literally (an observed series of actual collisions) or metaphorically (complex systems such as global finance, or in politics, where linkage is only a hypothesis).
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A cascade reaction or tandem reaction or domino reaction is a consecutive series of intramolecular organic reactions which often proceed via highly reactive intermediates. It allows the organic synthesis of complex multinuclear molecules from a single acyclic precursor. The substrate contains many functional groups that take part in chemical transformations one at the time. Often a functional group is generated in situ from the previous chemical transformation.
http://en.wikipedia.org/wiki/Domino_reaction