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

Dust mites, dead skin cells, sweat buildup and allergens accumulate over months, affecting your sleep quality and potentially triggering sneezing and congestion. —Lauren Jarvis-Gibson, Sacbee.com, 11 Apr. 2026

General maintenance schedules suggest once or twice a year, but allergy sufferers benefit from more frequent attention, especially during peak pollen seasons in spring and fall when indoor allergen loads tend to spike. —Lauren Jarvis-Gibson, Miami Herald, 10 Apr. 2026

Dust and allergens collect on the frame and surrounding area too. —Kansas City Star, 10 Apr. 2026

Dust buildup on your air vents and returns circulates allergens throughout your entire home every time your HVAC kicks on. —Lauren Jarvis-Gibson, Fort Worth Star-Telegram, 9 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