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definitions

allergen

[al-er-juh n, -jen]
See more synonyms for allergen on Thesaurus.com
noun Immunology.
  1. any substance, often a protein, that induces an allergy: common allergens include pollen, grasses, dust, and some medications.

Origin of allergen

First recorded in 1910–15; aller(gy) + -gen
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for allergen

dander, irritant, pollen, antigen, ragweed
British Dictionary definitions for allergen

allergen

noun
  1. any substance capable of inducing an allergy
Derived Formsallergenic, adjectiveallergenicity, noun
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 allergen
n.

substance causing allergy, 1912, from allergy on model of antigen.

Online Etymology Dictionary, © 2010 Douglas Harper
allergen in Medicine

allergen

[ăl′ər-jən]
n.
  1. A substance, such as pollen, that causes an allergy.
  2. antigen
Related formsal′ler•gen′ic (-jĕn′ĭk) adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
allergen in Science

allergen

[ăl′ər-jən]
  1. A substance, such as pollen, that causes an allergic reaction.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.