Phoebe vs pentad

Phoebe and pentad both are nouns.

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

As nouns, Phoebe and pentad are synonyms defined as:

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

Phoebe (noun)	pentad (noun)
(Greek mythology) a Titaness who became identified with Artemis as goddess of the Moon	the cardinal number that is the sum of four and one
the cardinal number that is the sum of four and one