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

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

For the pastina, I cook finely chopped carrots, onions, and celery until soft, then remove and blend about half until silky smooth.

From Salon

In a recent interview, Capp spoke with Salon about his “The Ringmaster,” his addiction, and those onion rings.

From Salon

Generous chunks of chicken are coated in a silky, spiced sauce made with crushed tomatoes, cream, onions, garlic, ginger and butter.

From Salon