Merriam-Webster's Collegiate® Dictionary, 11th Edition
POSSESSIVE
I. adjective
Date: 15th century
of, relating to, or constituting a word, a word group, or a grammatical case that denotes ownership or a relation analogous to ownership, manifesting possession or the desire to own or dominate, possessively adverb possessiveness noun
II. noun
Date: 15th century
a possessive word or word group,
2. the possessive case, a word in the possessive case