eggshell vs covering

eggshell and covering both are nouns.

Word	Noun	Adjective	Verb	Adverb
eggshell	Yes	No	No	No
covering	Yes	No	No	No

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

Other hypernyms of eggshell include cover, natural covering.

eggshell (noun)	covering (noun)
the exterior covering of a bird's egg	the act of protecting something by covering it
	the work of applying something
	the act of concealing the existence of something by obstructing the view of it
	an artifact that covers something else (usually to protect or shelter or conceal it)
	a natural object that covers or envelops