allergen
noun
al·ler·gen ˈa-lər-jən 
: a substance (such as pollen) that induces allergy
allergenic
ˌa-lər-ˈje-nik
adjective allergenicity
ˌa-lər-jə-ˈni-sə-tē
noun 
Example Sentences
common allergens, such as pollen
Recent Examples on the Web Mold causes reactions in three different ways: as an allergen, as an irritant and as a toxin. 
jsonline.com, 29 Aug. 2022 Hives are raised, itchy bumps that can form on your skin in response to a trigger, like an allergen or an infection, according to the American College of Allergy, Asthma, and Immunology (ACAAI). Korin Miller, SELF, 10 Aug. 2022 The body’s histamine response is attempting to dilute the offending allergen. Patricia A. Macculloch, The Conversation, 12 Aug. 2022 Wait, histamines, the chemical our bodies release when its defending against a potential allergen? Dana Mcmahan, The Courier-Journal, 12 July 2022 An anaphylactic reaction typically occurs within minutes or seconds of exposure to an allergen, according to the Mayo Clinic. Julie Marks, SELF, 11 June 2022 Creminelli Fine Meats of Salt Lake City is recalling about 4,207 pounds of ready-to-eat parmesan salami sticks due to misbranding and an undeclared allergen, the U.S. Department of Agriculture’s Food Safety and Inspection Service announced. Marc Bona, cleveland, 1 July 2022 The various flavors in those recalls contained an allergen that did not appear on the retail packaging. Chris Smith, BGR, 7 June 2022 This explains why your eyes feel itchy and your nose runs after breathing in an allergen such as pollen. Sara Gaynes Levy, SELF, 31 May 2022 See More
jsonline.com, 29 Aug. 2022 Hives are raised, itchy bumps that can form on your skin in response to a trigger, like an allergen or an infection, according to the American College of Allergy, Asthma, and Immunology (ACAAI). Korin Miller, SELF, 10 Aug. 2022 The body’s histamine response is attempting to dilute the offending allergen. Patricia A. Macculloch, The Conversation, 12 Aug. 2022 Wait, histamines, the chemical our bodies release when its defending against a potential allergen? Dana Mcmahan, The Courier-Journal, 12 July 2022 An anaphylactic reaction typically occurs within minutes or seconds of exposure to an allergen, according to the Mayo Clinic. Julie Marks, SELF, 11 June 2022 Creminelli Fine Meats of Salt Lake City is recalling about 4,207 pounds of ready-to-eat parmesan salami sticks due to misbranding and an undeclared allergen, the U.S. Department of Agriculture’s Food Safety and Inspection Service announced. Marc Bona, cleveland, 1 July 2022 The various flavors in those recalls contained an allergen that did not appear on the retail packaging. Chris Smith, BGR, 7 June 2022 This explains why your eyes feel itchy and your nose runs after breathing in an allergen such as pollen. Sara Gaynes Levy, SELF, 31 May 2022 See More Word History
Etymology
borrowed from German Allergen,, blend of allerg- (in Allergie allergy) and -gen (in Antigen antigen)
Note: See note at allergy.
First Known Use
circa 1907, in the meaning defined above
Kids Definition
allergen
noun
al·ler·gen ˈa-lər-jən
: a substance that causes an allergic reaction
Medical Definition
allergen
noun
al·ler·gen ˈal-ər-jən
: a substance that induces allergy
inhaled allergens
a suspected food allergen