The Collaborative International Dictionary of English v.0.48:

Possessive \Pos*sess"ive\, a. [L. possessivus: cf. F.
   possessif.]
   Of or pertaining to possession; having or indicating
   possession.
   [1913 Webster]

   Possessive case (Eng. Gram.), the genitive case; the case
      of nouns and pronouns which expresses ownership, origin,
      or some possessive relation of one thing to another; as,
      Homer's admirers; the pear's flavor; the dog's
      faithfulness.

   Possessive pronoun, a pronoun denoting ownership; as, his
      name; her home; my book.
      [1913 Webster]

WordNet (r) 3.0 (2006):

possessive case
    n 1: the case expressing ownership [syn: genitive, genitive
         case, possessive, possessive case]