deniable

from WordNet (r) 3.0 (2006)

deniable
    adj 1: capable of being denied or contradicted [ant:
           {undeniable}]

from The Collaborative International Dictionary of English v.0.48

Deniable \De*ni"a*ble\, a. [See {Deny}.]
   Capable of being, or liable to be, denied.
   [1913 Webster]

from Moby Thesaurus II by Grady Ward, 1.0

29 Moby Thesaurus words for "deniable":
      arguable, at issue, confutable, conjectural, contestable,
      controversial, controvertible, debatable, disputable, doubtable,
      doubtful, dubious, dubitable, iffy, in dispute, in doubt, in dubio,
      in question, mistakable, moot, open to doubt, open to question,
      problematic, questionable, refutable, speculative, suppositional,
      suspect, suspicious