roof vs natural covering

roof and natural covering both are nouns.

Word	Noun	Adjective	Verb	Adverb
roof	Yes	No	Yes	No
natural covering	Yes	No	No	No

As nouns, natural covering is a hypernym of roof; that is, natural covering is a word with a broader meaning than roof:

Other hypernyms of roof include cover, covering.

roof (noun)	natural covering (noun)
a protective covering that covers or forms the top of a building	a natural object that covers or envelops
protective covering on top of a motor vehicle
an upper limit on what is allowed
the inner top surface of a covered area or hollow space

roof (verb)	natural covering (verb)
provide a building with a roof; cover a building with a roof