grains of paradise vs herb

grains of paradise and herb both are nouns.

Word	Noun	Adjective	Verb	Adverb
grains of paradise	Yes	No	No	No
herb	Yes	No	No	No

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

grains of paradise: West African plant bearing pungent peppery seeds
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 grains of paradise include herbaceous plant.

grains of paradise (noun)	herb (noun)
West African plant bearing pungent peppery seeds	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