onion

/ˈʌnjən/

/ˈʌnjən/

Other forms: onions

An onion is a plant that grows as a bulb underground and can be harvested and eaten. Note: onions may be tasty, but they sure can make your breath stink.

Onions are bulbs, like tulips or daffodils — most of the plant is hidden in the soil, with roots stretching down and stalks that grow upward and eventually bloom with small flowers. Onions are typically harvested in the fall, and they come in many shapes, sizes, and colors, all of which can be eaten. The Latin root of onion, unionem, was used in colloquial Roman to mean both "a type of onion" and "a pearl."

Definitions of onion

1. noun

   bulbous plant having hollow leaves cultivated worldwide for its rounded edible bulb
   synonyms: Allium cepa, onion plant

   types:

   Allium ascalonicum, Allium cepa aggregatum, eschalot, multiplier onion, shallot

   type of onion plant producing small clustered mild-flavored bulbs used as seasoning

   Allium cepa viviparum, Egyptian onion, top onion, tree onion

   type of perennial onion grown chiefly as a curiosity or for early salad onions; having bulbils that replace the flowers

   Allium fistulosum, Japanese leek, Welsh onion

   Asiatic onion with slender bulbs; used as early green onions

   Allium haematochiton, red-skinned onion

   onion with white to deep red tunic; California

   type of:

   alliaceous plant

   bulbous plants having a characteristic pungent onion odor
2. noun

   an aromatic flavorful vegetable
   types:

   Bermuda onion

   mild flat onion grown in warm areas

   green onion, scallion, spring onion

   a young onion before the bulb has enlarged; eaten in salads

   Vidalia onion

   sweet-flavored onion grown in Georgia

   Spanish onion

   large mild and succulent onion; often eaten raw

   shallot

   small mild-flavored onion-like or garlic-like clustered bulbs used for seasoning

   purple onion, red onion

   flat mild onion having purplish tunics; used as garnish on hamburgers and salads

   type of:

   veg, vegetable, veggie

   edible seeds or roots or stems or leaves or bulbs or tubers or nonsweet fruits of any of numerous herbaceous plant
3. noun

   the bulb of an onion plant
   type of:

   bulb

   a modified bud consisting of a thickened globular underground stem serving as a reproductive structure