tranquility vs ataraxia

tranquility and ataraxia both are nouns.

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

As nouns, ataraxia is a hyponym of tranquility; that is, ataraxia is a word with a more specific, narrower meaning than tranquility:

tranquility (noun)	ataraxia (noun)
a disposition free from stress or emotion	peace of mind
a state of peace and quiet
an untroubled state; free from disturbances