corn salad vs herb

corn salad and herb both are nouns.

Word	Noun	Adjective	Verb	Adverb
corn salad	Yes	No	No	No
herb	Yes	No	No	No

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

corn salad: a plant of the genus Valerianella
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 corn salad include herbaceous plant.

corn salad (noun)	herb (noun)
a plant of the genus Valerianella	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