Kin means your family and relations. Kith and kin, next of kin, my own kin.
It is old-fashioned and survives mainly in fixed phrases. Next of kin is the live one: it is the person officially recorded as your closest relative, and hospitals, employers and the police use it constantly. Kith and kin means friends and family together, and kith on its own is entirely dead. Note kinship, which is alive and is the standard term in anthropology; and akin to, meaning similar to.
1nounkinYour family and relations.
“His next of kin was recorded as a cousin in Canada.”
kin is family relations.
Old English cynn meant a family, race or kind — the same word as kind, both the noun and the adjective. To be kind was originally to behave as one of the family, which is a better etymology than the word deserves.
Proto-Indo-European
*ǵenh₁-
Proto-Indo-European
*ǵn̥h₁yom
Proto-Germanic
*kunją — race, generation, descent
Proto-West Germanic
*kuni
Old English
cynn — kind, sort, rank
Middle English
kyn
English, today
kin
Built from
From Middle English kyn, from Old English cynn (“kind, sort, rank”), from Proto-West Germanic kuni, from Proto-Germanic kunją (“race, generation, descent”), from Proto-Indo-European ǵn̥h₁yom, from ǵenh₁- (“to produce”). Cognate with Scots kin (“relatives, kinfolk”), frr kinn, kenn (“gender, race, family, kinship”), Dutch kunne (“gender, sex”), Middle Low German kunne (“gender, sex, race, family, lineage”), Danish køn (“gender, sex”), Norwegian Bokmål and Norwegian Nynorsk kjønn (“gender, sex”), Swedish kön (“gender, sex”), Faroese and Icelandic kyn (“gender”), Finnish kunnia (“honour, glory”), izh kunnia (“reputation”), and through Indo-European, with Latin genus (“kind, sort, ancestry, birth”), Ancient Greek γένος (“kind, race”), Sanskrit जनस् (“kind, race”), Albanian dhen (“(herd of) small cattle”).
Etymology from Wiktionary, CC BY-SA