Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English


English definition of “allergy”


noun [C]    /ˈæl·ər·dʒi/
a condition that causes illness when someone eats certain foods or touches or breathes in certain substances : Your rash is caused by an allergy to peanuts . allergic    /əˈlɜr·dʒɪk/ adjective I’m allergic to cats .
(Definition of allergy noun from the Cambridge Academic Content Dictionary © Cambridge University Press)
Focus on the pronunciation of allergy

Definitions of “allergy” in other dictionaries

Word of the Day


the skill or activity of preparing and cooking food

Word of the Day


Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More