onion

noun

on·​ion ˈən-yən 

plural onions

1

: a widely cultivated Asian herbaceous plant (Allium cepa) of the amaryllis family that has a pungent edible bulb and that is closely related to the garlic, chive, and leek

also : its bulb

2

: any of various usually ornamental alliums (such as Allium amplectens or A. caeruleum) related to the onion

oniony

ˈən-yə-nē 

adjective

an oniony flavor

oniony meatloaf

Examples of onion in a Sentence

The recipe calls for chopped onions.

He is growing onions in the garden this year.

The recipe calls for chopped onion.

Recent Examples on the Web

Add the onion, garlic, cumin, paprikas and oregano. —Lynda Balslev, Mercury News, 28 May 2025

Tuesday, June 3, Beef Stew with carrots, potatoes, onions and celery, whole grain roll, Romaine salad and tomatoes, pineapples, milk. —Ramona Sentinel, San Diego Union-Tribune, 28 May 2025

McDonald's removed beef and onions from its supply chain after the CDC informed them of the outbreak, and Taylor Farms issued a recall of yellow onions in Oct. 2024, FOX Business reported last year. —Gretchen Eichenberg, FOXNews.com, 27 May 2025

Get the Super Max Pizza, with ground beef, cheese, onions and more, starting at $14.99 on May 28 (check your local Happy Joe's for availability). —Mike Snider, USA Today, 27 May 2025

Word History

Etymology

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

First Known Use

14th century, in the meaning defined at sense 1

Phrases Containing onion

• Bermuda onion
• green onion
• onion dome
• onion ring
• pearl onion
• sea onion
• Spanish onion
• spring onion

Rhymes for onion

• trunnion

Kids Definition

onion

noun

on·​ion ˈən-yən 

: a widely grown Asian herb related to the lilies and having edible bulbs that have a sharp odor and taste and are used as a vegetable and to season foods

also : its bulb