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

Others include milk, egg, wheat, fish, shellfish, sesame, peanuts and soy. Millions of people in the United States have food allergies or food sensitivities, and undeclared allergens are the most common reason for food recalls, according to the FDA. —Kristan Hawkins, Newsweek, 7 Feb. 2025

Undeclared allergens are a major cause of FDA recalls. —Abby Norman, Verywell Health, 4 Feb. 2025

Breadcrumbs sold for months throughout the United States contain an undeclared allergen and are being recalled for safety reasons, the Food and Drug Administration announced on its website on Jan. 28. —Christine Rousselle, Fox News, 1 Feb. 2025

While the signs and symptoms vary based on the allergen and individual, common symptoms of contact dermatitis include an itchy rash, leathery patches on the skin that are darker than usual, dry or cracked skin, bumps or blisters, swelling, burning, and tenderness. —Laura Baisas, Popular Science, 30 Jan. 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