any of numerous plants having stinging hairs that cause skin irritation on contact (especially of the genus Urtica or family Urticaceae)
Any plant whose foliage is covered with stinging, mildly poisonous hairs, causing an instant rash.
Especially, most species of herb genus Urtica, the stinging nettles
Of the nettle plant and similar physical causes, to sting, causing a rash in someone.
The word "nettle" comes from Old English, where it originally meant the stinging plant. Its roots trace back to Proto-West Germanic and are related to similar words in Dutch, German, and Danish.