seed vessel vs covering

seed vessel and covering both are nouns.

Word	Noun	Adjective	Verb	Adverb
seed vessel	Yes	No	No	No
covering	Yes	No	No	No

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

Other hypernyms of seed vessel include cover, natural covering.

seed vessel (noun)	covering (noun)
the ripened and variously modified walls of a plant ovary	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