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

At Spago, dishes from the iconic chain leaned into local flavors—bigeye ahi poke cones (the same served on the flight home), hamachi tostada, and caviar paired with Maui onion and taro hash browns, among them. —Susmita Baral, Travel + Leisure, 14 Apr. 2026

Add onion, 2 tablespoons broth, and remaining 2 teaspoons of garlic. —Cathy Thomas, Oc Register, 14 Apr. 2026

Add the onions and saute until soft without coloring, about 4 minutes. —Lynda Balslev, Mercury News, 14 Apr. 2026

Once completed, the $5 million acquisition will ensure the theater has a permanent home, a place where skateboarding clowns and leek-haired onions can continue to frolic and dance for decades to come. —Todd Martens, Los Angeles Times, 13 Apr. 2026

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