kernel vs caryopsis

kernel and caryopsis both are nouns.

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

As nouns, caryopsis is a hypernym of kernel; that is, caryopsis is a word with a broader meaning than kernel:

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

Other hypernyms of kernel include grain.

kernel (noun)	caryopsis (noun)
the choicest or most essential or most vital part of some idea or experience	dry seed-like fruit produced by the cereal grasses: e.g. wheat, barley, Indian corn
a single whole grain of a cereal
the inner and usually edible part of a seed or grain or nut or fruit stone