cassia bark vs bark

cassia bark and bark both are nouns.

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

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

cassia bark: aromatic bark of the cassia-bark tree; less desirable as a spice than Ceylon cinnamon bark
bark: tough protective covering of the woody stems and roots of trees and other woody plants

cassia bark (noun)	bark (noun)
aromatic bark of the cassia-bark tree; less desirable as a spice than Ceylon cinnamon bark	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