onion

American  

[uhn-yuhn] / ˈʌn yən /

noun

1. a plant, Allium cepa, of the amaryllis family, having an edible, succulent, pungent bulb.

2. any of certain similar plants.

3. the bulb of the onion plant.

4. the flavor or odor of this bulb.

5. Slang. a person.

   He's a tough onion.

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adjective

1. containing or cooked with onions.

   onion soup.

2. of, relating to, or resembling an onion.

idioms

1. know one's onions, to know one's subject or business thoroughly; be capable or proficient.

onion British  

/ ˈʌnjən /

noun

1. an alliaceous plant, Allium cepa, having greenish-white flowers: cultivated for its rounded edible bulb

2. the bulb of this plant, consisting of concentric layers of white succulent leaf bases with a pungent odour and taste

3. any of several related plants similar to A. cepa, such as A. fistulosum (Welsh onion)

4. slang to be fully acquainted with a subject

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onion More Idioms  

1. see know one's stuff (onions).

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Other Word Forms

• onionlike adjective
• oniony adjective

Etymology

Origin of onion

1325–75; Middle English onyon < Old French oignon < Latin ūniōn- (stem of ūniō ) a unity, large pearl, onion; union

Example Sentences

Growing up, my mother would make a simple salad of sliced cucumbers, tomatoes, red onions, and lemons, drizzled with salt, served alongside homemade curries, spiced rice and steamed fish fillets wrapped in banana leaf parcels.

From Salon

“It smells like onions in here,” Janie said, wrinkling her nose.

From Literature

Mama tried everything: red alder bark tea, hot water with onion juice.

From Literature

He emits a grunt of ale and onion.

From Literature

“People do seem to have changed their habits,” said Gudiño, who was stacking onions, tomatoes, greens and other produce atop his stand.

From Los Angeles Times