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

Examples of allergen in a Sentence

common allergens, such as pollen

Recent Examples on the Web

Experts recommend washing your duvet cover every week in hot water (130°F or higher) to kill allergens, dust mites, and bacteria. — Nafeesah Allen, Better Homes & Gardens, 19 Aug. 2026

That means scanning a 2D barcode can link you to an instruction manual, food allergens, coupons, show you what farm the product came from and whether the package is recyclable. — David Goldman, CNN Money, 18 Aug. 2026

Jones noted that sesame is now recognized as one of the nine major food allergens in the United States, and allergic reactions can range from mild itching or hives to life-threatening anaphylaxis. — Daryl Austin, USA Today, 12 Aug. 2026

Smart electronic shelf labels (ESLs) can also help instantly locate goods by using pick-to-light technology while displaying real-time reviews or even allergen warnings. — Gadi Graus, Forbes.com, 10 Aug. 2026

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 ˈal-ər-jən 

: a substance (as pollen) that causes allergy

allergenic

ˌal-ər-ˈjen-ik 

adjective

Medical Definition

allergen

noun

al·​ler·​gen ˈal-ər-jən 

: a substance that induces allergy

inhaled allergens

a suspected food allergen