salad green vs chicory

salad green and chicory both are nouns.

Word	Noun	Adjective	Verb	Adverb
salad green	Yes	No	No	No
chicory	Yes	No	No	No

As nouns, chicory is a hyponym of salad green; that is, chicory is a word with a more specific, narrower meaning than salad green:

Other hyponyms of salad green include lettuce, celtuce, curly endive, chicory escarole, endive, escarole, cress, salad burnet.

salad green (noun)	chicory (noun)
greens suitable for eating uncooked as in salads	crisp spiky leaves with somewhat bitter taste
	root of the chicory plant roasted and ground to substitute for or adulterate coffee
	perennial Old World herb having rayed flower heads with blue florets cultivated for its root and its heads of crisp edible leaves used in salads
	the dried root of the chicory plant: used as a coffee substitute