phratry vs family line

phratry and family line both are nouns.

Word	Noun	Adjective	Verb	Adverb
phratry	Yes	No	No	No
family line	Yes	No	No	No

As nouns, phratry and family line are synonyms defined as:

Other synonyms of phratry include family, folk, kinfolk, kinsfolk, sept.

phratry (noun)	family line (noun)
people descended from a common ancestor	people descended from a common ancestor