Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “onion”


noun [C or U] uk   /ˈʌn.jən/ us  
A2 a vegetable with a strong smell and flavour, made up of several layers surrounding each other tightly in a round shape, usually brown or red on the outside and white inside: I always cry when I'm chopping onions. Fry the onion and garlic for about two minutes.Types of vegetablePlants in general
(Definition of onion from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of onion?
Add Cambridge dictionaries to your browser to your website

Definitions of “onion” in other dictionaries

Word of the Day


When animals or people stampede, they all move quickly in the same direction, often because they are frightened.

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