[an-tee-ok-si-duh nt, an-tahy-]
  1. Chemistry. any substance that inhibits oxidation, as a substance that inhibits oxidative deterioration of gasoline, rubbers, plastics, soaps, etc.
  2. Biochemistry. an enzyme or other organic substance, as vitamin E or beta carotene, that is capable of counteracting the damaging effects of oxidation in animal tissues.
  1. Chemistry. of or relating to an antioxidant.

Origin of antioxidant

1925–30; anti- + oxidant (oxid(ize) + -ant) Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for antioxidant

Contemporary Examples of antioxidant

British Dictionary definitions for antioxidant


  1. any substance that retards deterioration by oxidation, esp of fats, oils, foods, petroleum products, or rubber
  2. biology a substance, such as vitamin C, vitamin E, or beta carotene, that counteracts the damaging effects of oxidation in a living organism
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

Word Origin and History for antioxidant

1920 (n.); 1932 (adj.), from anti- + oxidant.

Online Etymology Dictionary, © 2010 Douglas Harper

antioxidant in Science


[ăn′tē-ŏksĭ-dənt, ăn′tī-]
  1. A chemical compound or substance that inhibits oxidation. Certain vitamins, such as vitamin E, are antioxidants and may protect body cells from damage caused by the oxidative effects of free radicals.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.