waiver vs relinquishing

waiver and relinquishing both are nouns.

Word	Noun	Adjective	Verb	Adverb
waiver	Yes	No	No	No
relinquishing	Yes	No	No	No

As nouns, relinquishing is a hypernym of waiver; that is, relinquishing is a word with a broader meaning than waiver:

Other hypernyms of waiver include relinquishment.

waiver (noun)	relinquishing (noun)
a formal written statement of relinquishment	the act of giving up and abandoning a struggle or task etc.
	a verbal act of renouncing a claim or right or position etc.