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

According to the United States Environmental Protection Agency (EPA), the most effective way to improve indoor air quality is by reducing or removing the sources of allergens and ventilating your home with clean outdoor air. —Karen Berger, Verywell Health, 8 Oct. 2025

Vacuum Furniture Sofas and other upholstered furniture can accumulate dust, dead skin cells, and other allergens. —Karen Brewer Grossman, Southern Living, 8 Oct. 2025

This model protects against allergens like pollen and pet dander, smoke, dust, and does it all from a place of covert, inoffensive design. —Julia Harrison, Architectural Digest, 8 Oct. 2025

Upright Vacuum Deals Amazon Prime Big Deal Days is also serving up discounts on upright vacuum cleaners, like the best-selling Shark Lift-Away vacuum, which packs serious suction power and traps allergens with ease. —Toni Sutton, PEOPLE, 7 Oct. 2025

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