catalyst

noun

cat·​a·​lyst ˈka-tə-ləst 

1

: a person or thing that provokes or speeds significant change or action

a catalyst for economic growth

the catalyst behind the decision

Look at passionate young people from any era and you'll find impressive catalysts for change.

—Erin Blakemore

2

: a substance that enables a chemical reaction to proceed at a usually faster rate or under different conditions (as at a lower temperature) than otherwise possible

Depending on the catalyst used, the device either splits water to make hydrogen fuel or splits water and CO₂ to create syngas …

—Prachi Patel

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Word History of Catalyst

Catalyst is a fairly recent addition to the English language, first appearing at the start of the 20^th century with its chemistry meaning. It was formed from the word catalysis, another chemistry term which refers to a modification and especially an increase in the rate of a chemical reaction induced by material unchanged chemically at the end of the reaction. By the 1940s, the figurative sense of catalyst was in use for someone or something that quickly causes change or action.

Examples of catalyst in a Sentence

The bombing attack was the catalyst for war.

She was proud to be a catalyst for reform in the government.

Recent Examples on the Web

Brolley was the catalyst in scoring the first and third goals for a 5-0 halftime. —Patrick Z. McGavin, Chicago Tribune, 29 Apr. 2026

If the Minnesota Wild win what’s now become a best-of-three series against the powerhouse Dallas Stars, depth scoring could be the catalyst. —Michael Russo, New York Times, 27 Apr. 2026

David Bailey was one of the catalysts for Texas Tech, winning the Big 12 Championship after its defense finished third in the nation. —Antwan Staley, New York Daily News, 27 Apr. 2026

The case became a catalyst for mass protests against the repressive policies of Assad’s security forces. —Ghaith Alsayed, Los Angeles Times, 26 Apr. 2026

Word History

Etymology

see catalysis

First Known Use

1902, in the meaning defined at sense 2

Phrases Containing catalyst

• co-catalyst

Rhymes for catalyst

• catalysed

Kids Definition

catalyst

noun

cat·​a·​lyst ˈkat-ᵊl-əst 

1

: a substance that changes the rate of a chemical reaction but is itself unchanged at the end of the process

especially : such a substance that speeds up a reaction or enables it to proceed under milder conditions

2

: a person or event that quickly causes change or action

the scandal was a catalyst for reform

Medical Definition

catalyst

noun

cat·​a·​lyst ˈkat-ᵊl-əst 

: a substance (as an enzyme) that enables a chemical reaction to proceed at a usually faster rate or under different conditions (as at a lower temperature) than otherwise possible