Chemistry. a substance that causes or accelerates a chemical reaction without itself being affected.
something that causes activity between two or more persons or forces without itself being affected.
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.
a person whose talk, enthusiasm, or energy causes others to be more friendly, enthusiastic, or energetic.

Origin of catalyst

First recorded in 1900–05; cataly(sis) + (-i)st
Related formsself-cat·a·lyst, nounsem·i·cat·a·lyst, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for catalyst

Contemporary Examples of catalyst

Historical Examples of catalyst

  • You'll be pleasantly surprised at how this approach will act as a catalyst.

  • I come back soon and gif you the catalyst for that last reaction.

    Beyond the Vanishing Point

    Raymond King Cummings

  • You do not know where we secure the catalyst your people seek.

    The Colors of Space

    Marion Zimmer Bradley

  • A catalyst failed briefly in its task, then resumed, but the damage had been done.

    The Short Life

    Francis Donovan

  • This simple act may have been the catalyst which gave Burl the solution to the problem.

    The Forgotten Planet

    Murray Leinster

British Dictionary definitions for catalyst



a substance that increases the rate of a chemical reaction without itself suffering any permanent chemical changeCompare inhibitor (def. 2)
a person or thing that causes a change
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for catalyst

"substance which speeds a chemical reaction but itself remains unchanged," 1902, formed in English (on analogy of analyst) from catalysis. Figurative use by 1943.

Online Etymology Dictionary, © 2010 Douglas Harper

catalyst in Medicine




A substance, usually used in small amounts relative to the reactants, that modifies and increases the rate of a reaction without being consumed in the process.
Related formscat′a•lytic (kăt′l-ĭtĭk) adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

catalyst in Science



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.
Related formscatalytic adjective (kăt′l-ĭtĭk)
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

catalyst in Culture



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


The term catalyst is often used to refer to the prime agent of any change: “She was the catalyst for the reorganization.”
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.