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

• 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

For those with allergies, these particles can be inhaled and trigger annoying symptoms like sneezing, a runny nose, or itchy eyes. —Ashlyn Needham, Southern Living, 5 Sep. 2025

Some fragrances can make your skin more sensitive to sunlight, leading to what’s sometimes called a sun allergy. —Leslie Baumann, Miami Herald, 4 Sep. 2025

Spring is often seen as the peak of allergy season, but fall is also a common time of year to suffer from hay fever. —Maggie Horton, People.com, 3 Sep. 2025

This filtration system ensures that your floors are getting their most thorough clean, while also ridding your space of irritants like dust that can cause allergy flare-ups. —Yelena Moroz Alpert, Architectural Digest, 3 Sep. 2025

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