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.

---

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

---

onion More Idioms  

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

---

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

So when my grocery store ran one of those five-for-five promotions on frozen vegetables — a retail siren song I have never successfully resisted — I tossed a couple of bags of frozen onion into my cart.

From Salon

Mandy Carter, also from Reddish, told BBC Radio Manchester: "Each week is different, so it could be potatoes, onions, tomatoes and carrots to help make things like soup."

From BBC

When I finally nailed a roast chicken — buttered and oiled, stuffed with lemon wedges and hunks of onion and fennel — I felt like a goddess.

From Salon

The company, Irvine-based Ventura Foods, recalled 3,556 cases of the dressing that could be contaminated by “black plastic planting material” in the granulated onion used, according to an alert issued by the U.S.

From Los Angeles Times

The report specified that the “foreign objects” in question are black plastic planting material found in granulated onion used to make the dressing.

From Salon