casava vs shrub

casava and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
casava	Yes	No	No	No
shrub	Yes	No	No	No

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

casava: any of several plants of the genus Manihot having fleshy roots yielding a nutritious starch
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of casava include bush.

casava (noun)	shrub (noun)
any of several plants of the genus Manihot having fleshy roots yielding a nutritious starch	a low woody perennial plant usually having several major stems