kiss of peace vs salutation

kiss of peace and salutation both are nouns.

Word	Noun	Adjective	Verb	Adverb
kiss of peace	Yes	No	No	No
salutation	Yes	No	No	No

As nouns, salutation is a hypernym of kiss of peace; that is, salutation is a word with a broader meaning than kiss of peace:

kiss of peace: (Roman Catholic Church) a greeting signifying Christian love for those assisting at the Eucharist
salutation: (usually plural) an acknowledgment or expression of good will (especially on meeting)

Other hypernyms of kiss of peace include greeting.

kiss of peace (noun)	salutation (noun)
(Roman Catholic Church) a greeting signifying Christian love for those assisting at the Eucharist	(usually plural) an acknowledgment or expression of good will (especially on meeting)
	an act of honor or courteous recognition
	word of greeting used to begin a letter