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, carrots and celery and sauté for about 5 minutes, until softened. — ABC News, 30 Sep. 2026

Steelhead trout, a member of the salmon family, was soft with a hint of sweetness and paired beautifully with the green beans and onion. — Kansas City Star, 30 Sep. 2026

Other offerings blend global flavors — like the birria ramen made with ramen noodles, cilantro and onions in a birria beef broth. — Tanasia Kenney, Charlotte Observer, 29 Sep. 2026

Scotto spent years washing dishes before he was trusted to chop onions or peel potatoes. — Tatiana Sataua, Fortune, 26 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