The Collaborative International Dictionary of English v.0.48:

Rhetorical \Rhe*tor"ic*al\, a. [L. rhetoricus, Gr. ????. See
   Rhetoric.]
   Of or pertaining to rhetoric; according to, or exhibiting,
   rhetoric; oratorical; as, the rhetorical art; a rhetorical
   treatise; a rhetorical flourish.
   [1913 Webster]

         They permit him to leave their poetical taste
         ungratified, provided that he gratifies their
         rhetorical sense.                        --M. Arnold.
   [1913 Webster] -- Rhe*tor"ic*al*ly, adv. --
   Rhe*tor"ic*al*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

rhetorical
    adj 1: of or relating to rhetoric; "accepted two or three verbal
           and rhetorical changes I suggested"- W.A.White; "the
           rhetorical sin of the meaningless variation"- Lewis
           Mumford
    2: given to rhetoric, emphasizing style at the expense of
       thought; "mere rhetorical frippery" [ant: unrhetorical]