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

Rugs trap dust, dirt, allergens, odors, pet hair, dander, and more. — Rebecca Jones, Southern Living, 7 Nov. 2026

And certain plant protein varieties may contain common allergens like soy or nuts. — Maggie Donahue, HEALTH, 5 Nov. 2026

While a pumpkin seed allergy is rare, walnuts are a type of tree nut, a common allergen. — Brittany Lubeck, Verywell Health, 28 Oct. 2026

Washing cotton sheets in hot water can kill dust mites and remove allergens. — Abby Monteil, The Spruce, 26 Oct. 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