- The definition of an allergy is a sensitivity to a specific substance which causes a negative bodily reaction, such as sneezing, wheezing, itching or difficulty breathing.
Breaking out in hives when getting stung by a bee is an example of an allergy.
- a hypersensitivity to a specific substance (such as a food, pollen, dust, etc.) or condition (as heat or cold) which in similar amounts or degrees is harmless to most people: it is manifested in a physiological disorder
- a strong aversion
Origin of allergyGerman allergie ; from Classical Greek allos, other (see else) + -ergeia, as in energeia (see energy)
- An abnormally high sensitivity to certain substances, such as pollens, foods, or microorganisms. Common indications of allergy may include sneezing, itching, and skin rashes.
- Informal An adverse sentiment; antipathy: an allergy to cocktail parties.
Origin of allergyGerman Allergie : Greek allos, other; see allo– + Greek ergon, action; see werg- in Indo-European roots.
- (pathology, immunology) A disorder of the immune system causing adverse reactions to substances (allergens) not harmful to most and marked by the body's production of histamines and associated with atopy, anaphylaxis, and asthma.
- (pathology) Any condition of hypersensitivity to a substance.
- Altered susceptibility to a first treatment as exhibited in reaction to a subsequent one.
- (informal) An antipathy, as toward a person or activity.
- He has an allergy to reality TV.
From German Allergie. Coined by Austrian pediatrician Clemens von Pirquet in 1906 from Ancient Greek ἄλλος (allos, “other”) + ἔργον (ergon, “work, activity”), on the model of Energie.