allergy

UK: /ˈælə^rdʒi/ US: /ˈælɚdʒi/ ,(al′ər jē)

Inflections of 'allergy' (n): npl: allergies

WordReference Random House Learner's Dictionary of American English © 2025

al•ler•gy /ˈælɚdʒi/   n. [countable] , pl. -gies. 

1. Immunology a reaction of the body to an otherwise harmless substance, typically marked by skin rash, swelling of tissues of the nose or throat, sneezing, or wheezing.
2. a strong dislike:
   an allergy to rude people.

WordReference Random House Unabridged Dictionary of American English © 2025

al•ler•gy  (al′ər jē), n., pl. -gies. 

1. Medicine, Immunology 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. Immunology hypersensitivity to the reintroduction of an allergen. Cf. anaphylaxis.
3. [Informal.] a strong dislike or aversion, as toward a person or activity:
   He has an allergy to hard work.

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

Collins Concise English Dictionary © HarperCollins Publishers::

allergy / ˈælədʒɪ/ noun ( -gies)

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. aversion

Etymology: 20th Century: from German Allergie (indicating a changed reaction), from Greek allos other + ergon activity