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 rains also set off a chain reaction up current. —Bill Kearney, Sun Sentinel, 29 Apr. 2026

Some analysts have raised alarms about how weakness in a key node of the web, like OpenAI, could set off a chain reaction that could threaten the entire AI ecosystem. —Rob Wile, NBC news, 28 Apr. 2026

The chain reaction in the graphite core led to a steam explosion that ripped the reactor apart and lifted its massive 1,000-ton lid. —Georgina Jedikovska, Interesting Engineering, 26 Apr. 2026

The story follows a seemingly simple blind date that goes wildly, and painfully, off the rails, setting off a chain reaction among a tightly wound group of friends and family members. —Dave Quinn, PEOPLE, 23 Apr. 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