catalyst

American  

[kat-l-ist] / ˈkæt l ɪst /

noun

1. Chemistry. a substance that causes or accelerates a chemical reaction without itself being affected.

2. something that causes activity between two or more persons or forces without itself being affected.

3. a person or thing that precipitates an event or change.

   His imprisonment by the government served as the catalyst that helped transform social unrest into revolution.

4. a person whose talk, enthusiasm, or energy causes others to be more friendly, enthusiastic, or energetic.

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catalyst British  

/ ˈkætəlɪst /

noun

1. a substance that increases the rate of a chemical reaction without itself suffering any permanent chemical change Compare inhibitor

2. a person or thing that causes a change

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catalyst Scientific  

/ kăt′l-ĭst /

1. A substance that starts or speeds up a chemical reaction while undergoing no permanent change itself. The enzymes in saliva, for example, are catalysts in digestion.

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catalyst Cultural  

1. In chemistry, a substance that causes a chemical reaction to occur but is not itself involved in the reaction.

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Discover More

The term catalyst is often used to refer to the prime agent of any change: “She was the catalyst for the reorganization.”

Other Word Forms

• self-catalyst noun
• semicatalyst noun

Etymology

Origin of catalyst

First recorded in 1900–05; cataly(sis) + (-i)st

Explanation

A catalyst is an event or person causing a change. Getting kicked out of your parents' house might be a catalyst for becoming more independent. The noun catalyst is something or someone that causes a change and is derived from the Greek word katalύein, meaning "to dissolve." It can be somewhat ordinary, like when moving to a warmer climate was the catalyst for getting a short, sporty haircut. Or it can be major, like how the assassination of Archduke Franz Ferdinand of the Austro-Hungarian Empire is said to be a catalyst of World War I.

Example Sentences

A U.S. declaration could serve as a catalyst for a more coherent Western approach to Antarctic governance as the Madrid Protocol review approaches.

From The Wall Street Journal • Apr. 8, 2026

I like to mention there is no reason to catch a falling knife until a catalyst presents itself.

From Barron's • Apr. 8, 2026

For one, Materne thinks growing adoption of “usage-based” performance metrics is one potential catalyst.

From MarketWatch • Apr. 6, 2026

Marl-Brock had been telling others and that was "the catalyst" for what happened later.

From BBC • Apr. 4, 2026

Then, I'll release hydrazine, very slowly, over the iridium catalyst, to turn it into N2 and H2.

From "The Martian" by Andy Weir

Related Words

• impetus
• incentive
• motivation
• stimulant