parsley vs herb

parsley and herb both are nouns.

Word	Noun	Adjective	Verb	Adverb
parsley	Yes	No	No	No
herb	Yes	No	No	No

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

parsley: aromatic herb with flat or crinkly leaves that are cut finely and used to garnish food
herb: aromatic potherb used in cookery for its savory qualities

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

parsley: annual or perennial herb with aromatic leaves
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 parsley include herbaceous plant.

parsley (noun)	herb (noun)
aromatic herb with flat or crinkly leaves that are cut finely and used to garnish food	aromatic potherb used in cookery for its savory qualities
annual or perennial herb with aromatic leaves	a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests