quintet vs pentad

quintet and pentad both are nouns.

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

As nouns, quintet and pentad are synonyms defined as:

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

quintet (noun)	pentad (noun)
a musical composition for five performers	the cardinal number that is the sum of four and one
five people considered as a unit
a set of five similar things considered as a unit
five performers or singers who perform together
the cardinal number that is the sum of four and one