quintuplet vs pentad

quintuplet and pentad both are nouns.

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

As nouns, quintuplet and pentad are synonyms defined as:

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

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

quintuplet (noun)	pentad (noun)
a set of five similar things considered as a unit	the cardinal number that is the sum of four and one
one of five children born at the same time from the same pregnancy
the cardinal number that is the sum of four and one