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

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

The 2026 World Cup can be a catalyst to boost it to an even higher orbit. — Michael Lewis, Forbes.com, 5 Aug. 2026

And though the Valks punctuated the run with a prolific 31-point outlay in the third quarter, Nakase harped on the defensive end of the floor as the true catalyst that accelerated the Valkyries’ comeback. — Christian Babcock, Mercury News, 5 Aug. 2026

Now, researchers at the Shibaura Institute of Technology in Japan have developed a cheap, platinum-free catalyst that solves a major roadblock for high-energy lithium–oxygen batteries. — Mrigakshi Dixit, Interesting Engineering, 5 Aug. 2026

Advertisement Putin’s invasion of Ukraine in 2022 served as the catalyst for some strands of this cooperation, though some of it predated the invasion. — Ariane Tabatabai, Time, 4 Aug. 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