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

The 90s Supreme, with Italian tomatoes, pepperoni, sausage, onions, mushrooms and peppers. —Heidi Finley, Charlotte Observer, 28 May 2026

Remove from heat and return onion and scallions to pan; stir to combine. —Shilpa Uskokovic, Bon Appetit Magazine, 28 May 2026

The crunchiness of the crispy onions really seal the deal on this casserole, which is packed with rice, cheese, chicken, and broccoli. —Jenna Sims, Southern Living, 28 May 2026

The sauce derives its exciting flavor from a unique ingredients blend featuring pickles, chilis, mustard, mayo and onion. —Bestreviews, Mercury News, 27 May 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