tranquility vs calm

tranquility and calm both are nouns.

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

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

Other hypernyms of tranquility include calmness, composure, equanimity.

tranquility (noun)	calm (noun)
a disposition free from stress or emotion	steadiness of mind under stress
a state of peace and quiet	wind moving at less than 1 knot; 0 on the Beaufort scale
an untroubled state; free from disturbances

tranquility (adjective)	calm (adjective)
	(of weather) free from storm or wind
	not agitated; without losing self-possession

tranquility (verb)	calm (verb)
	cause to be calm or quiet as by administering a sedative to
	make steady
	make calm or still
	become quiet or calm, especially after a state of agitation