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

To a large oven-safe skillet or a sauté pan over medium heat, add the oil, onion, and poblanos and season with salt to taste. — ABC News, 23 Sep. 2026

Cover and cook, stirring occasionally, until onion is translucent and tender, 8–10 minutes. — Shilpa Uskokovic, Bon Appetit Magazine, 22 Sep. 2026

Smoked turkey is piled on bolillo bread, then loaded with avocado, shredded lettuce, tomato, onion, pickled jalapenos, ranch and lots of cilantro. — Justin Brown, AJC.com, 20 Sep. 2026

Place the potatoes on the prepared pan, breaking up any frozen clumps; add onion and bell pepper. — Erin Merhar, Southern Living, 19 Sep. 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
• French onion soup
• green onion
• onion dome
• onion ring
• onion soup
• 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