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

Alongside heaping plates of spiced rice — filled with generous chunks of tender mutton and buttery marrow and slivers of fried golden onions — were bowls of a humble condiment.

From Salon

“Offal wasn’t rationed during the war, and my mother resorted to the sort of food she’d eaten as a child: tripe and onions, brains, tongue and braised rabbit,” he told the Independent in 2009.

From The Wall Street Journal

I could get a hot dog topped with mustard, relish and onions served on a steamed bun.

From The Wall Street Journal

My mini-blender has long been a quiet ally — mincing onions when my joints aren’t cooperating, blitzing together a very good chickpea salad in no time.

From Salon

On one side were the vegetables and herbs: tomatoes, onions, mushrooms, mini broccoli, chives, parsley, tarragon and chervil.

From Salon