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

Federal law dictates that the nine leading allergens, including peanuts and soy, be listed on food packaging when relevant. — Sasha Rogelberg, Fortune, 20 July 2026

For children with allergies or asthma, remove the carpet from their bedroom to prevent pollutants and allergens that can build up in the carpet. — Dr. Lauren Zajac, Boston Herald, 19 July 2026

This prevents your air conditioner from running efficiently while also circulating allergens around your house. — Brandee Gruener, Southern Living, 19 July 2026

Hypoallergenic bedding like pillows, comforters and bedsheets is designed to resist common indoor allergens like pollen, pet dander and dust mites. — Jen Christensen, CNN Money, 18 July 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