The Collaborative International Dictionary of English v.0.48:

Genitive \Gen"i*tive\, a. [L. genitivus, fr. gignere, genitum,
   to beget: cf. F. g['e]nitif. See Gender.] (Gram.)
   Of or pertaining to that case (as the second case of Latin
   and Greek nouns) which expresses source or possession. It
   corresponds to the possessive case in English.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Genitive \Gen"i*tive\, n. (Gram.)
   The genitive case.
   [1913 Webster]

   Genitive absolute, a construction in Greek similar to the
      ablative absolute in Latin. See Ablative absolute.
      [1913 Webster]

WordNet (r) 3.0 (2006):

genitive
    adj 1: serving to express or indicate possession; "possessive
           pronouns"; "the genitive endings" [syn: possessive,
           genitive]
    n 1: the case expressing ownership [syn: genitive, genitive
         case, possessive, possessive case]