allergen

noun

al·​ler·​gen ˈa-lər-jən How to pronounce allergen (audio)
: a substance (such as pollen) that induces allergy
allergenic
ˌa-lər-ˈje-nik How to pronounce allergen (audio)
adjective
allergenicity
ˌa-lər-jə-ˈni-sə-tē How to pronounce allergen (audio)
noun

Examples of allergen in a Sentence

common allergens, such as pollen
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Smart electronic shelf labels (ESLs) can also help instantly locate goods by using pick-to-light technology while displaying real-time reviews or even allergen warnings. — Gadi Graus, Forbes.com, 10 Aug. 2026 An allergen and ingredient list is set out at the Overland Park location, and it is referenced in the back at the Shawnee one. — Sophie Lindberg, Kansas City Star, 9 Aug. 2026 By the 1990s, research suggested that certain childhood infections helped the body tune its immune system, instead of overreacting to dust, pollen and other allergens. — Baltimore Sun, Boston Herald, 9 Aug. 2026 Existing strategies for managing dog allergies focus primarily on controlling the body's immune response rather than reducing allergen production at its source, according to the company's August study. — Michelle Del Rey, USA Today, 7 Aug. 2026 See All Example Sentences for allergen

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

Time Traveler
The first known use of allergen was circa 1907

Browse Nearby Words

Allen wrench
allergen
allergic
See all Nearby Words

Cite this Entry

“Allergen.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/allergen. Accessed 11 Aug. 2026.

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Kids Definition

allergen

noun
al·​ler·​gen ˈal-ər-jən How to pronounce allergen (audio)
: a substance (as pollen) that causes allergy
allergenic
ˌal-ər-ˈjen-ik How to pronounce allergen (audio)
adjective

Medical Definition

allergen

noun
al·​ler·​gen ˈal-ər-jən How to pronounce allergen (audio)
: a substance that induces allergy
inhaled allergens
a suspected food allergen

More from Merriam-Webster on allergen

Nglish: Translation of allergen for Spanish Speakers

Britannica.com: Encyclopedia article about allergen

Last Updated: - Updated example sentences
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