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

Let’s peel back the layers of the onion and figure out, was she born this way, or did society make her this way? —Mark Hughes, Forbes.com, 19 June 2026

The burger at Bar Avoja in Los Angeles is made with a prime brisket patty, Tillamook cheddar, dill pickles, onion fonduta and herb rémoulade on a brioche bun, Food & Wine reported. —Teresa Mull, FOXNews.com, 18 June 2026

Others are hyperseasonal, such as kalamboki (roasted corn with feta butter) and aginares souvlaki (artichoke skewers with bell pepper, red onion and a yogurt side). —Scott Hocker, TheWeek, 18 June 2026

This recipe is ideal for fans of sausage, peppers, and onions. —Jenna Sims, Southern Living, 18 June 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