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

The dual-compartment reactor uses a single photon of sunlight to drive a highly efficient chain reaction. —Mrigakshi Dixit, Interesting Engineering, 12 June 2026

Senior first baseman Kaitlyn Streiler suffered a broken hand on April 18, setting off a chain reaction that included Beals shifting to first. —Michael Osipoff, Chicago Tribune, 11 June 2026

The Hyundai then struck another car, which caused a chain reaction that involved a third vehicle. —Harriet Ramos, Fort Worth Star-Telegram, 11 June 2026

While there’s some disagreement among close observers of the project about when exactly that chain reaction must begin to meet the 2031 deadline, the consensus is that major decisions need to be made in roughly the next two months. —Elliott Wenzler, Denver Post, 9 June 2026

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