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

Last week, Novartis agreed to buy allergy drugmaker Excellergy for up to $2 billion.

From The Wall Street Journal • Mar. 31, 2026

The acquisition adds an early-stage drug candidate, an anti-IgE antibody, to complement Novartis’s 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

Janice, my oldest sister, had an allergy that made one nostril sing like a bird at night, so we called her Whistling Nose.

From "The Joy Luck Club" by Amy Tan

Related Words

• hay fever