dill weed vs herb

dill weed and herb both are nouns.

Word	Noun	Adjective	Verb	Adverb
dill weed	Yes	No	No	No
herb	Yes	No	No	No

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

dill weed (noun)	herb (noun)
aromatic threadlike foliage of the dill plant used as seasoning	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