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

This first-of-its-kind portable device has been designed to detect gluten and allergens with lab-like precision. —Mrigakshi Dixit, Interesting Engineering, 6 Jan. 2026

In fact, thanks to more time spent indoors with closed windows, your bedding is likely harboring even more body oils, skin cells, and potential allergens than in other seasons. —Kate Van Pelt, The Spruce, 5 Jan. 2026

This setting is designed to eliminate bacteria and allergens like dust mites from sheets, towels, and undergarments. —Brandee Gruener, Southern Living, 5 Jan. 2026

Use an extendable duster or microfiber cloth to access hard-to-reach spots where dust and allergens tend to accumulate. —Nafeesah Allen, Better Homes & Gardens, 4 Jan. 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