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[kat-l-ist] /ˈkæt l ɪst/
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.
1900-05; cataly(sis) + (-i)st
Related forms
self-catalyst, noun
semicatalyst, noun Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the web for catalysts
  • Step two would be converting the gas to ethanol using chemical catalysts.
  • Enzymes are proteins that act as catalysts, speeding up chemical reactions.
  • In warm weather, trees release volatile chemicals that act as catalysts for smog.
  • Realizing this vision will transform libraries from guardians of tradition to catalysts of a vast change.
  • The catalysts for revolt are common: restricted liberties, rising food costs, and high unemployment.
  • Economic austerity was only one of the catalysts for the trend toward efficient living.
  • And currency traders have found new potential catalysts for revaluation.
  • Sensitive dates have often been catalysts for renewed trouble.
  • Employees are continually confronted with new challenges that become catalysts for building new capabilities.
  • These are catalysts added to vaccines to improve their efficacy and reduce the amount of active ingredients required.
British Dictionary definitions for catalysts


a substance that increases the rate of a chemical reaction without itself suffering any permanent chemical change Compare inhibitor (sense 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
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Word Origin and History for catalysts



"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
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catalysts in Medicine

catalyst cat·a·lyst (kāt'l-ĭst)
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.

cat'a·lyt'ic (kāt'l-ĭt'ĭk) adj.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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catalysts 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.

catalytic adjective (kāt'l-ĭt'ĭk)
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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catalysts in Culture
catalyst [(kat-uh-list)]

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

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