Onion (noun)

1. A bulbous plant with a characteristic strong smell and taste, consisting of several layers of edible translucent white or yellowish leaves surrounding a central leafless stalk, used in cooking.
2. The bulb of such a plant, consisting of concentric layers, used as a vegetable.

Origin:

From old english ūnġe, from latin unio "onion", from proto-indo-european *h1óynos.

Examples:

1. He chopped an onion for the soup.
2. She cried while cutting the onions.
3. The onion is a staple in many cuisines.
4. The onion has a pungent aroma.
5. The onion is a good source of vitamin C.