What does the term "kinship" mean?

Your relationship within your family ,,,,i think you will find,,,,,

2 of 2 has it right.

Growing up I often heard the term "kith and kin" which means the same as "friends and relatives" in my home if that helps.

your part of our family even though your not related

"Kinship is a relationship between any entities that share a genealogical origin, through either biological, cultural, or historical descent. In anthropology the kinship system includes people related both by descent and marriage, while usage in biology includes descent and mating. Human kinship relations through marriage are commonly called "affinity" in contrast to "descent" (also called "consanguinity"), although the two may overlap in marriages among those of common descent. Family relations as sociocultural genealogy lead back to gods[1] (see mythology, religion), animals that were in the area or natural phenomena (as in origin stories).

Kinship is one of the most basic principles for organizing individuals into social groups, roles, categories, and genealogy. Family relations can be represented concretely (mother, brother, grandfather) or abstractly after degrees of relationship. A relationship may have relative purchase (e.g., father is one regarding a child), or reflect an absolute (e.g., status difference between a mother and a childless woman). Degrees of relationship are not identical to heirship or legal succession. Many codes of ethics consider the bond of kinship as creating obligations between the related persons stronger than those between strangers, as in Confucian filial piety."
Source and further information:
http://en.wikipedia.org/wiki/Kinship