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 20th 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
From education and job training programs, infrastructure improvements, the emergence of small and medium-sized businesses catering to the growing workforce, increased housing developments, and greater nonprofit engagement, these investments are a catalyst for great change.
—
Allan Swan, Forbes.com, 29 July 2025
Bo Mack will never forget the moment that became the catalyst for his decades-long weight loss journey.
—Vanessa Etienne, People.com, 28 July 2025
Kirby Yates’ signing to a one-year, $13 million deal toward the end of the winter was an odd catalyst for critics saying the Dodgers’ spending was destroying the integrity of the sport.
—Fabian Ardaya, New York Times, 27 July 2025
Netflix However, narratively speaking, Virginia's death makes sense and ends up being the catalyst that propels the story forward.
—Megan McCluskey, Time, 25 July 2025
See All Example Sentences for catalyst
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Allan Swan, Forbes.com, 29 July 2025
Bo Mack will never forget the moment that became the catalyst for his decades-long weight loss journey.
—Vanessa Etienne, People.com, 28 July 2025
Kirby Yates’ signing to a one-year, $13 million deal toward the end of the winter was an odd catalyst for critics saying the Dodgers’ spending was destroying the integrity of the sport.
—Fabian Ardaya, New York Times, 27 July 2025
Netflix However, narratively speaking, Virginia's death makes sense and ends up being the catalyst that propels the story forward.
—Megan McCluskey, Time, 25 July 2025
See All Example Sentences for catalyst
Cite this Entry
“Catalyst.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/catalyst. Accessed 7 Aug. 2025.
Copy CitationKids 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
Love words? Need even more definitions?
Merriam-Webster unabridged
Share