expiation vs salvation

expiation and salvation both are nouns.

Word	Noun	Adjective	Verb	Adverb
expiation	Yes	No	No	No
salvation	Yes	No	No	No

As nouns, salvation is a hypernym of expiation; that is, salvation is a word with a broader meaning than expiation:

expiation: the act of atoning for sin or wrongdoing (especially appeasing a deity)
salvation: (theology) the act of delivering from sin or saving from evil

Other hypernyms of expiation include redemption.

expiation (noun)	salvation (noun)
the act of atoning for sin or wrongdoing (especially appeasing a deity)	(theology) the act of delivering from sin or saving from evil
compensation for a wrong	a means of preserving from harm or unpleasantness
	saving someone or something from harm or from an unpleasant situation
	the state of being saved or preserved from harm