kinship group vs kin group

kinship group and kin group both are nouns.

Word	Noun	Adjective	Verb	Adverb
kinship group	Yes	No	No	No
kin group	Yes	No	No	No

As nouns, kinship group and kin group are synonyms defined as:

kinship group and kin group: group of people related by blood or marriage

Other synonyms of kinship group include clan, kin, kindred, tribe.

kinship group (noun)	kin group (noun)
group of people related by blood or marriage	group of people related by blood or marriage