These words refer to the people connected to one by blood or marriage. Kin is a general word for such people but is now somewhat archaic, except in phrases like next-of-kin . Relatives is the common term, for which relations can substitute – especially as the word of choice to indicate humorous or serious disparagement of the people to whom one is related. When used, kin is more likely to concentrate on blood relationship, whereas the other two are wider in scope by including in-laws as well. Kin is always construed as plural.

Family is a much more restricted term, referring only to one’s closest blood relatives , usually to those people actually living together in one household: a family composed of mother, father, one grandfather, and three children. The word can apply more widely to those people, past and present, bearing the same family name: a distinguished British family over three generations. Kinsmen often points to this same idea: He brilliantly upheld the honour of a long line of kinsmen . Unlike kin , the word has a singular form: a kinsman (or kinswoman ) of mine. Kindred can refer to relatives , to lineage, or to a looser fraternal or tribal group: a clan in which the kindred are loyal to the same totem.

Kinfolk and kinfolks are informal version of kinsfolk which, like kin , appears preponderantly in the U.S. South and has no singular form. The word suggests a good many relatives who keep in touch or who act together, as in a clan. By contrast, one might have relatively few known kin and might not be socially close to them at all.