kei apple vs shrub

kei apple and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
kei apple	Yes	No	No	No
shrub	Yes	No	No	No

As nouns, shrub is a hypernym of kei apple; that is, shrub is a word with a broader meaning than kei apple:

kei apple: vigorous South African spiny shrub grown for its round yellow juicy edible fruits
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of kei apple include bush.

kei apple (noun)	shrub (noun)
vigorous South African spiny shrub grown for its round yellow juicy edible fruits	a low woody perennial plant usually having several major stems