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

Home offices are the perfect place to run a small HEPA air purifier to remove pollen and other allergens from the air. —Stephen Underwood, Hartford Courant, 29 May 2026

Estrogen levels can influence mast cells, the white blood cells that sound the body’s alarm in response to allergens and threats. —Helen Carefoot, Flow Space, 29 May 2026

For example, if allergies are due to pollen, staying indoors, using sunglasses or rinsing off your face after exposure can help decrease allergen load around your eyes. —Neelam Patadia, The Conversation, 27 May 2026

Tackling these chores on a regular basis can prevent messes from getting out of hand and reduce allergens. —Madeline Buiano, Martha Stewart, 24 May 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