devil nettle vs herb

devil nettle and herb both are nouns.

Word	Noun	Adjective	Verb	Adverb
devil nettle	Yes	No	No	No
herb	Yes	No	No	No

As nouns, herb is a hypernym of devil nettle; that is, herb is a word with a broader meaning than devil nettle:

devil nettle: a stinging herb of tropical America
herb: a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests

Other hypernyms of devil nettle include herbaceous plant.

devil nettle (noun)	herb (noun)
a stinging herb of tropical America	aromatic potherb used in cookery for its savory qualities
	a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests