onion

[uhn-yuhn]

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.

adjective

1. containing or cooked with onions.

   onion soup.

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

onion

/ 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

Other Word Forms

• onionlike adjective
• oniony adjective

Word History and Origins

Origin of onion¹

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

Word History and Origins

Origin of onion¹

C14: via Anglo-Norman from Old French oignon, from Latin unio onion, related to _union

Idioms and Phrases

Idioms

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

see know one's stuff (onions).

Example Sentences

There isn’t a seafood counter, and a small “Georgia Grown” section offered mostly potatoes, onions and peanuts, though it will carry more items in the summer months.

Read more on The Wall Street Journal

"We work hard to include vegetables like sweet peppers, onion and potatoes. This enables us to improve the taste and the nutritional value."

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Under normal circumstances she would have been thrilled to visit Russia, a fascinating place where the tops of important buildings were shaped like onions and everyone’s favorite soup was made of beets.

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The cook had followed the recipe to perfection: chunks of tender stew meat simmered with onions, garlic, potatoes, parsnips, carrots, and tomatoes, seasoned with caraway and, of course, the paprika.

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She, too, seemed to be misty.eyed all of sudden; perhaps it was a consequence of some errant fumes from the onion soup being served at another table.

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