five vs quintuplet

five and quintuplet both are nouns.

Word	Noun	Adjective	Verb	Adverb
five	Yes	Yes	No	No
quintuplet	Yes	No	No	No

As nouns, five and quintuplet are synonyms defined as:

five and quintuplet: the cardinal number that is the sum of four and one

Other synonyms of five include 5, cinque, fin, fivesome, Little Phoebe, pentad, Phoebe, quint, quintet, V.

five (noun)	quintuplet (noun)
a playing card or a domino or a die whose upward face shows five pips	a set of five similar things considered as a unit
a team that plays basketball	one of five children born at the same time from the same pregnancy
the cardinal number that is the sum of four and one	the cardinal number that is the sum of four and one

five (adjective)	quintuplet (adjective)
being one more than four