noun, plural catalyses [kuh-tal-uh-seez] .
Chemistry. the causing or accelerating of a chemical change by the addition of a catalyst.
an action between two or more persons or forces, initiated by an agent that itself remains unaffected by the action: social catalyses occasioned by controversial writings.

1645–55; < Neo-Latin < Greek katálȳsis dissolution, equivalent to katalȳ́(ein) to dissolve (kata- cata- + lȳ́ein to loosen) + -sis -sis

catalytic [kat-l-it-ik] , adjective, noun
catalytical, adjective
catalytically, adverb
anticatalytic, adjective, noun
anticatalytically, adverb
noncatalytic, adjective, noun
noncatalytically, adverb
self-catalysis, noun
semicatalytic, adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To catalytic
World English Dictionary
catalysis (kəˈtælɪsɪs)
n , pl -ses
acceleration of a chemical reaction by the action of a catalyst
[C17: from New Latin, from Greek katalusis, from kataluein to dissolve]

catalytic (ˌkætəˈlɪtɪk)
of or relating to catalysis; involving a catalyst

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
Word Origin & History

1655, "dissolution," from Gk. katalysis "dissolution," from katalyein "to dissolve," from kata- "down" + lyein "to loosen" (see lose). Chemical sense is attested from 1836.

from Gk. katalytikos "able to dissolve," from katalysis (see catalysis).
Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
American Heritage
Medical Dictionary

catalysis ca·tal·y·sis (kə-tāl'ĭ-sĭs)
n. pl. ca·tal·y·ses (-sēz')
The action of a catalyst, especially an increase in the rate of a chemical reaction.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
American Heritage
Science Dictionary
catalyst   (kāt'l-ĭst)  Pronunciation Key 
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.
Cite This Source
Example sentences
The catalytic converter on your exhaust system contains cerium and lanthanum.
The work paved the way for technologies such as hydrogen fuel cells and
  automobile catalytic converters.
The modern fuel injection system works with a three-way catalytic converter to
  cut pollution.
Rare earths are used in automotive catalytic converters and for refining
  petroleum products.
Copyright © 2014, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature