allergy

American  

[al-er-jee] / ˈæl ər dʒi /

noun

plural

allergies

1. an abnormal reaction of the body to a previously encountered allergen introduced by inhalation, ingestion, injection, or skin contact, often manifested by itchy eyes, runny nose, wheezing, skin rash, or diarrhea.

2. hypersensitivity to the reintroduction of an allergen.

3. Informal. a strong dislike or aversion, as toward a person or activity.

   He has an allergy to hard work.

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allergy British  

/ ˈælədʒɪ /

noun

1. a hypersensitivity to a substance that causes the body to react to any contact with that substance. Hay fever is an allergic reaction to pollen

2. informal aversion

   he has an allergy to studying

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allergy Scientific  

/ ăl′ər-jē /

1. An abnormally high immunologic sensitivity to certain stimuli such as drugs, foods, environmental irritants, microorganisms, or physical conditions, such as temperature extremes. These stimuli act as antigens, provoking an immunological response involving the release of inflammatory substances, such as histamine, in the body. Allergies may be innate or acquired in genetically predisposed individuals. Common symptoms include sneezing, itching, and skin rashes, though in some individuals symptoms can be severe.

2. See also anaphylactic shock

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allergy Cultural  

1. A highly sensitive reaction of the body to certain substances, such as pollen, that are present in amounts that do not affect most people. Common indications of allergy include sneezing, skin rashes, itching, and runny nose.

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Etymology

Origin of allergy

1910–15; < Greek áll ( os ) other + -ergy < Greek -ergia, equivalent to érg ( on ) activity + -ia -y ³

Example Sentences

Novartis agreed to acquire Excellergy for up to $2 billion, expanding its immunology portfolio with food allergy treatments.

From The Wall Street Journal • Mar. 27, 2026

The Swiss pharmaceutical company said Friday that the deal for privately-held Excellergy will add a drug candidate in early-stage trials with potential to complement its existing allergy portfolio.

From The Wall Street Journal • Mar. 27, 2026

We have a cultural allergy to first-mover status.

From Barron's • Mar. 12, 2026

She says there was a "catalogue of errors" that contributed to her son's death when he was given milk containing cow's milk protein at school, despite his allergy being on record.

From BBC • Mar. 5, 2026

“I am perfectly healthy, madam, apart from a slight dustmite allergy, and I don’t think even you can do anything about that. No. What I want from you is your Book.”

From "Artemis Fowl" by Eoin Colfer

Related Words

• hay fever