onion onion /ˈʌnjən/

noun

1. An aromatic flavorful vegetable  ( onion )
   an aromatic flavorful vegetable
    She added some diced onion to the salad to give it an aromatic touch.
   She added some diced onion to the salad to give it an aromatic touch.
   
   
2. Bulbous plant having hollow leaves cultivated worldwide for its rounded edible bulb  ( Allium cepa , onion , onion plant )
   bulbous plant having hollow leaves cultivated worldwide for its rounded edible bulb
   
   
3. The bulb of an onion plant  ( onion )
   the bulb of an onion plant
    I always tear up when I chop the bulb of an onion plant.
   I always tear up when I chop the bulb of an onion plant.