pica-pica vs herb

pica-pica and herb both are nouns.

Word	Noun	Adjective	Verb	Adverb
pica-pica	Yes	No	No	No
herb	Yes	No	No	No

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

pica-pica: 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 pica-pica include herbaceous plant.

pica-pica (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