Source : Webster's Revised Unabridged Dictionary (1913)

Surprising \Sur*pris"ing\, a.
   Exciting surprise; extraordinary; of a nature to excite
   wonder and astonishment; as, surprising bravery; a surprising
   escape from danger. -- {Sur*pris"ing*ly}, adv. --
   {Sur*pris"ing*ness}, n.

   Syn: Wonderful; extraordinary; unexpected; astonishing;
        striking.

Source : WordNet®

surprisingness
     n : extraordinariness by virtue of being unexpected; "the
         unexpectedness of the warm welcome" [syn: {unexpectedness}]
         [ant: {expectedness}]