catalyst

noun

cat·​a·​lyst ˈka-tə-ləst 

1

: 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

2

: an agent that provokes or speeds significant change or action

That waterway became the catalyst of the area's industrialization.

He was the catalyst in the native uprising.

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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

The char also provides a structure for a complex ecosystem of helpful bacteria and other organisms that boost crop yields and can act as a catalyst that makes essential nutrients like nitrogen and potassium more available to plants. —Erik Kobayashi-Solomon, Forbes.com, 28 Aug. 2025

Now, Ragweed is intent on making the reunion permanent, and Folk sees a Stillwater return as the catalyst for that — as well as a chance to continue basking in the band’s 2025 homecoming. —Josh Crutchmer, Rolling Stone, 27 Aug. 2025

The process involves a catalyst that may surprise chemistry teachers. —ArsTechnica, 27 Aug. 2025

But the experience with crypto mining, where GPUs are run inside dusty data centers that leave GPUs caked in dirt, were a catalyst for what became CoreWeave’s secret sauce. —Reed Albergotti, semafor.com, 27 Aug. 2025

Word History

Etymology

see catalysis

First Known Use

1902, in the meaning defined at sense 1

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