chain reaction

noun

1

a

: a series of events so related to each other that each one initiates the next

b

: a number of events triggered by the same initial event

2

: a self-sustaining chemical or nuclear reaction yielding energy or products that cause further reactions of the same kind

chain-react

ˈchān-rē-ˈakt 

intransitive verb

Examples of chain reaction in a Sentence

Increased oil prices could trigger a chain reaction in the economy.

Recent Examples on the Web

Should the bold promises of AI fall short, the dependence among these major AI players could trigger a devastating chain reaction, causing a widespread collapse similar to the 2008 Great Financial Crisis. —Jeffrey Sonnenfeld, Fortune, 7 Oct. 2025

However, thermal runaway can occur when one battery cell overheats and triggers a chain reaction, leading to extreme heat, flames, and structural damage. —Sujita Sinha, Interesting Engineering, 7 Oct. 2025

With that, Cora began the chain reaction that shaped a 4-3 loss to the Yankees, one that set up a do-or-die Game 3 of what has been a tense Wild Card Series. —Jen McCaffrey, New York Times, 2 Oct. 2025

The fourth wave, in which two large pieces of debris incite a chain reaction of other collisions, has yet to occur. —IEEE Spectrum, 30 Sep. 2025

Word History

First Known Use

1892, in the meaning defined at sense 1a

Rhymes for chain reaction

• abstraction
• attraction
• compaction
• contraction
• detraction
• diffraction
• distraction
• exaction
• extraction
• impaction
• inaction
• infraction

Kids Definition

chain reaction

noun

1

: a series of events so related to each other that each one sets the next one going

2

: a chemical or nuclear reaction producing energy or products that cause further reactions of the same kind

Medical Definition

chain reaction

noun

: a self-sustaining chemical or nuclear reaction yielding energy or products that cause further reactions of the same kind