phellem vs bark

phellem and bark both are nouns.

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

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

phellem: (botany) outer tissue of bark; a protective layer of dead cells
bark: tough protective covering of the woody stems and roots of trees and other woody plants

phellem (noun)	bark (noun)
(botany) outer tissue of bark; a protective layer of dead cells	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