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.

Did you know?

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

This inflection from being a loss-making company to profit-generating one is often a big catalyst for the re-rating of a stock. —Trefis Team, Forbes.com, 22 Aug. 2025

As a catalyst, Yih cited recent business decisions made by Ulta CEO Kecia Steelman, who took over the reins of the company earlier this year. —Lisa Kailai Han, CNBC, 22 Aug. 2025

The proposal now sweeps more industries: printing, sealing, machinery, technical textiles, broader medical packaging and pharmaceutical ingredients—even military and explosives applications, plus general industrial uses like solvents and catalysts. —Alexandra Harrell, Sourcing Journal, 22 Aug. 2025

While there was not an explicit catalyst for the decline of tech and AI stocks decline this week, investors said Altman’s comments and the MIT report could be contributing to negative momentum. —John Towfighi, CNN Money, 20 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