cascara vs bark

cascara and bark both are nouns.

Word	Noun	Adjective	Verb	Adverb
cascara	Yes	No	No	No
bark	Yes	No	Yes	No

As nouns, bark is a hypernym of cascara; that is, bark is a word with a broader meaning than cascara:

cascara: dried bark of the cascara buckthorn used as a laxative
bark: tough protective covering of the woody stems and roots of trees and other woody plants

cascara (noun)	bark (noun)
dried bark of the cascara buckthorn used as a laxative	a sailing ship with 3 (or more) masts
	the sound made by a dog
	a noise resembling the bark of a dog
	tough protective covering of the woody stems and roots of trees and other woody plants