serenity vs calmness

serenity and calmness both are nouns.

Word	Noun	Adjective	Verb	Adverb
serenity	Yes	No	No	No
calmness	Yes	No	No	No

As nouns, calmness is a hypernym of serenity; that is, calmness is a word with a broader meaning than serenity:

Other hypernyms of serenity include calm, composure, equanimity.

serenity (noun)	calmness (noun)
a disposition free from stress or emotion	steadiness of mind under stress
the absence of mental stress or anxiety	a feeling of calm; an absence of agitation or excitement
	an absence of strong winds or rain