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

In fact, anything in the onion family is good in that regard – leeks, shallots, garlic, and chives as well as the more familiar yellow, white, or red onion bulbs. —Lauren Jarvis-Gibson, Charlotte Observer, 24 Mar. 2026

Lessons come true and fast among recipes for amaranth salad, wild onion soup and chokecherry pudding. —Scott Hocker, TheWeek, 24 Mar. 2026

Measure out ¼ cup onion from 1 large white onion, finely chopped, and set aside. —Rebecca Firkser, Bon Appetit Magazine, 23 Mar. 2026

In fact, anything in the onion family is good in that regard – leeks, shallots, garlic, and chives as well as the more familiar yellow, white, or red onion bulbs. —Kansas City Star, 23 Mar. 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