The Collaborative International Dictionary of English v.0.48:

Incomparable \In*com"pa*ra*ble\, a. [L. incomparabilis: cf. F.
   incomparable. See In- not, and Comparable.]
   Not comparable; admitting of no comparison with others;
   unapproachably eminent; without a peer or equal; matchless;
   peerless; transcendent.
   [1913 Webster]

         A merchant of incomparable wealth.       --Shak.
   [1913 Webster]

         A new hypothesis . . . which hath the incomparable Sir
         Isaac Newton for a patron.               --Bp.
                                                  Warburton.
   -- In*com"pa*ra*ble*ness, n. -- In*com"pa*ra*bly, adv.
   [1913 Webster]

         Delights incomparably all those corporeal things. --Bp.
                                                  Wilkins.
   [1913 Webster]

WordNet (r) 3.0 (2006):

incomparably
    adv 1: in an incomparable manner or to an incomparable degree;
           "she is incomparably gifted" [syn: incomparably,
           uncomparably] [ant: comparably]

Moby Thesaurus II by Grady Ward, 1.0:

24 Moby Thesaurus words for "incomparably":
   egregiously, eminently, exceedingly, far and away, inimitably,
   invincibly, matchlessly, nulli secundus, par excellence,
   paramountly, peerlessly, preeminently, prominently, superlatively,
   supremely, surpassingly, the most, to crown all, transcendently,
   unbeatably, uniquely, unmatchably, unsurpassably, unsurpassedly