Nettle (noun)

1. A herbaceous plant with small greenish flowers, which has fine stiff hairs on the stems and leaves that cause a stinging sensation when touched.
2. An irritant or source of irritation.

Origin:

Old english netele, of germanic origin; related to dutch netel and german nessel.

Examples:

1. He brushed against a nettle and his arm was covered in red welts.
2. The nettle tea was believed to have medicinal properties.
3. The soup was made from nettle leaves.
4. The nettle was used as a natural dye for cloth.
5. The nettle is a common weed in gardens and fields.