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

And some ingredients that should have been listed on product labels — potential allergens such as milk, wheat, eggs, and dyes — have at times gone undisclosed, according to a series of food recalls. —David Hilzenrath, CBS News, 7 Mar. 2025

Soy is among the top eight allergens in the United States.35 Soy allergies can have serious side effects. —Larell Scardelli, Verywell Health, 5 Mar. 2025

This powerful air purifier is built for large rooms, taking on pet odors, allergens and more. —Maria Correa, Miami Herald, 3 Mar. 2025

Undeclared allergens remain a persistent issue, with labeling mistakes posing serious risks for people with food allergies. —Stephanie Gravalese, Forbes, 3 Mar. 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