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free radical

noun, Chemistry, Biochemistry
1.
an atom or molecule that bears an unpaired electron and is extremely reactive, capable of engaging in rapid chain reactions that destabilize other molecules and generate many more free radicals: in the body, deactivated by antioxidants, uric acid, and certain enzyme activities.
Compare diradical.
Origin
1895-1900
1895-1900
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
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Examples from the web for free radical
  • Our skin is a hydrocarbon so the chemistry of free radical reaction still applies.
British Dictionary definitions for free radical

free radical

noun
1.
an atom or group of atoms containing at least one unpaired electron and existing for a brief period of time before reacting to produce a stable molecule Sometimes shortened to radical Compare group (sense 10)
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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free radical in Medicine

free radical n.

  1. An uncharged atom or group of atoms having at least one unpaired electron, which makes it highly reactive.

  2. An organic compound having some unpaired valence electrons; a normal byproduct of oxidation reactions in metabolism.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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free radical in Science
free radical  
An atom or group of atoms that has at least one unpaired electron and is therefore unstable and highly reactive. In animal tissues, free radicals can damage cells and are believed to accelerate the progression of cancer, cardiovascular disease, and age-related diseases.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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Difficulty index for free radical

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Word Value for free

7
7
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