serenity vs tranquility

serenity and tranquility both are nouns.

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

As nouns, serenity and tranquility are synonyms defined as:

Other synonyms of serenity include placidity, quiet, repose, tranquillity.

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

Other hypernyms of serenity include quietness, quietude, tranquillity.

serenity (noun)	tranquility (noun)
a disposition free from stress or emotion	a disposition free from stress or emotion
the absence of mental stress or anxiety	a state of peace and quiet
	an untroubled state; free from disturbances