sprout vs greens

sprout and greens both are nouns.

Word	Noun	Adjective	Verb	Adverb
sprout	Yes	No	Yes	No
greens	Yes	No	No	No

As nouns, greens is a hypernym of sprout; that is, greens is a word with a broader meaning than sprout:

sprout: a newly grown bud (especially from a germinating seed)
greens: any of various leafy plants or their leaves and stems eaten as vegetables

Other hypernyms of sprout include green, leafy vegetable.

sprout (noun)	greens (noun)
a newly grown bud (especially from a germinating seed)	any of various leafy plants or their leaves and stems eaten as vegetables
any new growth of a plant such as a new branch or a bud

sprout (verb)	greens (verb)
put forth and grow sprouts or shoots
produce buds, branches, or germinate