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actinide

[ ak-tuh-nahyd ]
/ ˈæk təˌnaɪd /
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noun Chemistry.
any element of the actinide series.
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Origin of actinide

1940–45; actin- + -ide, on the model of lanthanide
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

British Dictionary definitions for actinide

actinide
/ (ˈæktɪˌnaɪd) /

noun
a member of the actinide seriesAlso called: actinon

Word Origin for actinide

C19: from actino- + -ide
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

Scientific definitions for actinide

actinide
[ ăktə-nīd′ ]

Any of a series of chemically similar metallic elements with atomic numbers ranging from 89 (actinium) to 103 (lawrencium). All of these elements are radioactive, and two of the elements, uranium and plutonium, are used to generate nuclear energy. See Periodic Table.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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