genitive (en)

(adjective) of, relating to, or constituting a grammatical case marking typically a relationship of possessor or source / (adjective) expressing a relationship that in some inflected languages is often marked by a genitive case / (noun) a syntactic construction in English in which possession is marked both by the preposition of and a noun or pronoun in the possessive case (as in “A friend of Bob's is a friend of mine”)