allergy

noun

al·​ler·​gy ˈa-lər-jē 

plural allergies

1

: altered bodily reactivity (such as hypersensitivity) to an antigen in response to a first exposure

a bee venom allergy so severe that a second sting may be fatal

2

: exaggerated or pathological immunological reaction (as by sneezing, difficult breathing, itching, or skin rashes) to substances, situations, or physical states that are without comparable effect on the average individual

3

: medical practice concerned with allergies

4

: a feeling of antipathy or aversion

Synonyms of allergy

• dislike
• hatred
• disliking
• distaste

Examples of allergy in a Sentence

Many people have some form of allergy.

independent-minded people who seem to have an allergy to any control from the government

Recent Examples on the Web

But the remote doctors can manage some of the same routine issues that all primary care doctors do, Ireland said, including moderate respiratory infections, allergies and chronic conditions like diabetes, high cholesterol and depression. —Martha Bebinger, NPR, 9 Jan. 2026

Ahead of the front, temperatures surged into the 80s, breaking daily heat records over the past two days, while breezy conditions spread a haze of cedar pollen across Austin, aggravating seasonal allergies for many residents. —Mary Wasson, Austin American Statesman, 9 Jan. 2026

If moisture isn’t allowed to evaporate, mold and bacteria spores can have an impact on your indoor air quality too and lead to allergies, skin irritation, and other health issues. —Karen Brewer Grossman, Southern Living, 9 Jan. 2026

Improper preparation and allergies increase health risks. —Trista Chan, Health, 8 Jan. 2026

Word History

Etymology

borrowed from German Allergie "heightened reaction to an antigen to which an individual has been previously exposed," from all- all- + -ergie, in Energie energy, or directly from its source, Greek -ergeia, taken to mean "action, response"

Note: The term was introduced, along with allergisch allergic and Allergen allergen, by the German physician Clemens Peter Freiherr von Pirquet (1874-1929) in "Allergie," Münchener medizinische Wochenschrift, 53. Jahrgang, Nr. 30 (July 24, 1906), pp. 1457-58.

First Known Use

1908, in the meaning defined at sense 1

Phrases Containing allergy

• allergy shot
• anti-allergy

Kids Definition

allergy

noun

al·​ler·​gy ˈal-ər-jē 

plural allergies

1

: exaggerated or abnormal reaction (as by sneezing, itching, or rashes) to substances, situations, or physical states that do not have such a strong effect on most people

2

: a feeling of dislike

Medical Definition

allergy

noun

al·​ler·​gy ˈal-ər-jē 

plural allergies

1

: altered bodily reactivity (as hypersensitivity) to an antigen in response to a first exposure

his bee-venom allergy may render a second sting fatal

2

: exaggerated or pathological reaction (as by sneezing, respiratory embarrassment, itching, or skin rashes) to substances, situations, or physical states that are without comparable effect on the average individual

3

: medical practice concerned with allergies