caryopsis vs barleycorn

caryopsis and barleycorn both are nouns.

Word	Noun	Adjective	Verb	Adverb
caryopsis	Yes	No	No	No
barleycorn	Yes	No	No	No

As nouns, barleycorn is a hyponym of caryopsis; that is, barleycorn is a word with a more specific, narrower meaning than caryopsis:

caryopsis: dry seed-like fruit produced by the cereal grasses: e.g. wheat, barley, Indian corn
barleycorn: a grain of barley

Other hyponyms of caryopsis include amaranth, wheat berry, kernel, rye.

caryopsis (noun)	barleycorn (noun)
dry seed-like fruit produced by the cereal grasses: e.g. wheat, barley, Indian corn	a grain of barley
	a grain of barley