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

Both menus also come with special wellness sections for health-minded travelers, listing calorie and allergen content from dishes teeming with local produce and proteins in their purest forms. —Condé Nast, Condé Nast Traveler, 7 Apr. 2026

Wawa is recalling four of its 16-ounce drinks sold across five states, including the Philadelphia area, due to a possible undeclared milk allergen. —Frederick Sutton Sinclair, CBS News, 4 Apr. 2026

Latex promotes continuous airflow for cooler sleep and offers inherent resistance to allergens and dust mites, supporting a cleaner, healthier sleep environment. —Tory Johnson, ABC News, 1 Apr. 2026

Additionally, common allergens such as soy or nuts may be present in some varieties of plant proteins. —Anna Giorgi, Verywell Health, 1 Apr. 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