tranquillity vs quiet

tranquillity and quiet both are nouns.

Word	Noun	Adjective	Verb	Adverb
tranquillity	Yes	No	No	No
quiet	Yes	Yes	Yes	Yes

As nouns, tranquillity and quiet are synonyms defined as:

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

As nouns, tranquillity and quiet are synonyms defined as:

Other synonyms of tranquillity include tranquility.

tranquillity (noun)	quiet (noun)
a disposition free from stress or emotion	a disposition free from stress or emotion
a state of peace and quiet	the absence of sound
an untroubled state; free from disturbances	a period of calm weather
	an untroubled state; free from disturbances

tranquillity (adjective)	quiet (adjective)
	free of noise or uproar; or making little if any sound
	characterized by an absence or near absence of agitation or activity
	(of the sun) characterized by a low level of surface phenomena, such as sunspots
	(of a body of water) free from disturbance by heavy waves
	in a softened tone
	not showy or obtrusive

tranquillity (verb)	quiet (verb)
	make calm or still
	become quiet or quieter

tranquillity (adverb)	quiet (adverb)
	with little or no activity or no agitation (`quiet' is a nonstandard variant for `quietly')