Dictionary

onion

noun on·ion \ˈən-yən\

: a round vegetable that is usually white, yellow, or red and has a strong smell and taste

Full Definition of ONION

: a widely cultivated Asian herb (Allium cepa) of the lily family with pungent edible bulbs; also : its bulb

: any of various plants of the same genus as the onion

— on·iony \-yə-nē\ adjective

See onion defined for English-language learners

See onion defined for kids

Middle English, from Anglo-French oignon, from Latin union-, unio

First Known Use: 14th century

ONION Defined for Kids

noun on·ion \ˈən-yən\

: the roundish edible bulb of a plant related to the lily that has a sharp odor and taste and is used as a vegetable and to season foods

Next Word in the Dictionary: onion couchPrevious Word in the Dictionary: -onicAll Words Near: onion

What made you want to look up onion? Please tell us where you read or heard it (including the quote, if possible).

Put-downs with flair

How to use a word that (literally) drives some people nuts.

Test your vocab with our fun, fast game

Ailurophobia, and 9 other unusual fears