oynoun

Noun

onion (plural onions)

1. A monocotyledonous plant (Allium cepa), allied to garlic, used as vegetable and spice.
   • Some of the weeds that cause an undesirable flavor in milk are: onion, tarweed, scaleweed, garlic, mustard, pepper grass.1944, Oregon. Agricultural experiment station, Circular of Information - Issues 323-395, page 3
2. The bulb of such a plant.
   • My eyes are stinging from the chopped onions.
3. Any of various plants, mostly of the genus Allium, that are more or less similar to Allium cepa.
   • Many onions are delicious; domesticated onions such as Allium cepa and Allium fistulosum are especially good, but even wild onions such as Allium canadense and Allium validum are nice in small doses.
4. (slang) Of a drug, an ounce.
5. (obsolete, slang) A ball.
6. (obsolete, slang) A watch-seal.
   • […] M was a Magsman, frequenting Pall-Mall; / N was a Nose that turned chirp on his pal; / O was an Onion, possessed by a swell; / P was a Pannie, done niblike and well. […]1846, George William MacArthur Reynolds, The Mysteries of London, page 60

See all 8 meanings of onion