quadruplet vs quartette

quadruplet and quartette both are nouns.

Word	Noun	Adjective	Verb	Adverb
quadruplet	Yes	No	No	No
quartette	Yes	No	No	No

As nouns, quadruplet and quartette are synonyms defined as:

quadruplet and quartette: a set of four similar things considered as a unit

Other synonyms of quadruplet include quadruple, quartet.

quadruplet (noun)	quartette (noun)
a set of four similar things considered as a unit	a musical composition for four performers
one of four children born at the same time from the same pregnancy	four people considered as a unit
the cardinal number that is the sum of three and one	a set of four similar things considered as a unit
	four performers or singers who perform together