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The intrinsic property in radiation that produces photochemical activity.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(ˈæk təˌnɪz əm)

the property of radiation by which chemical effects are produced.
[1835–45; < Greek aktīn-, s. of aktis (see actino-) + -ism]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.


the ability of light and heat and other forms of radiant energy to cause chemical changes, as hormonal changes in birds causing them to migrate or brood. — actinic, adj.
See also: Heat
-Ologies & -Isms. Copyright 2008 The Gale Group, Inc. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.actinism - the property of radiation that enables it to produce photochemical effects
property - a basic or essential attribute shared by all members of a class; "a study of the physical properties of atomic particles"
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