family vs family line

family and family line both are nouns.

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

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

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

family (noun)	family line (noun)
primary social group; parents and children	people descended from a common ancestor
people descended from a common ancestor
a social unit living together
(biology) a taxonomic group containing one or more genera
a collection of things sharing a common attribute
an association of people who share common beliefs or activities
a loose affiliation of gangsters in charge of organized criminal activities
a person having kinship with another or others