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

Ingredients: The meatballs are made with ground 100% Angus beef, prized for its marbling, plus Parmesan and Romano cheeses, panko, garlic, onion, and a few spices. —Karla Walsh, Southern Living, 16 May 2025

Roasting fresh chile peppers, onions, and garlic gives the salsa a deep, smoky flavor, while tomatillos and lime keep it bright and tangy. —Elizabeth Fogarty, Better Homes & Gardens, 15 May 2025

An entire pig is filled with a mix of yellow peas, white rice, onions, and garlic and seasoned with a blend of spices, such as cumin, green onions, smoked paprika, salt, and pepper. —Cat Sposato, AFAR Media, 15 May 2025

Sprinkle one slice of bread with onions, then neatly arrange the seasoned kimchi on top. —Cathy Thomas, San Diego Union-Tribune, 14 May 2025

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