aeration vs natural action

aeration and natural action both are nouns.

Word	Noun	Adjective	Verb	Adverb
aeration	Yes	No	No	No
natural action	Yes	No	No	No

As nouns, natural action is a hypernym of aeration; that is, natural action is a word with a broader meaning than aeration:

aeration: the process of exposing to air (so as to purify)
natural action: a process existing in or produced by nature (rather than by the intent of human beings)

Other hypernyms of aeration include action, activity, natural process.

aeration (noun)	natural action (noun)
the act of charging a liquid with a gas making it effervescent	a process existing in or produced by nature (rather than by the intent of human beings)
the process of exposing to air (so as to purify)