[ al-er-jee ]
/ ˈæl ər dʒi /

noun, plural al·ler·gies.

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.
hypersensitivity to the reintroduction of an allergen. Compare anaphylaxis.
Informal. a strong dislike or aversion, as toward a person or activity: He has an allergy to hard work.

Origin of allergy

1910–15; < Greek áll(os) other + -ergy < Greek -ergia, equivalent to érg(on) activity + -ia -y3

Example sentences from the Web for allergy

British Dictionary definitions for allergy

/ (ˈælədʒɪ) /

noun plural -gies

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
informal aversion he has an allergy to studying

Word Origin for allergy

C20: from German Allergie (indicating a changed reaction), from Greek allos other + ergon activity

Medical definitions for allergy

[ ălər-jē ]


An abnormally high acquired sensitivity to certain substances, such as drugs, pollens, or microorganisms, that may include such symptoms as sneezing, itching, and skin rashes.

Scientific definitions for allergy

[ ălər-jē ]

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. See also anaphylactic shock.

Cultural definitions for allergy


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.