The Collaborative International Dictionary of English v.0.48:

Exceedingly \Ex*ceed"ing*ly\, adv.
   To a very great degree; beyond what is usual; surpassingly.
   It signifies more than very.
   [1913 Webster]

WordNet (r) 3.0 (2006):

exceedingly
    adv 1: to an extreme degree; "extremely cold"; "extremely
           unpleasant" [syn: extremely, exceedingly, super,
           passing]

Moby Thesaurus II by Grady Ward, 1.0:

47 Moby Thesaurus words for "exceedingly":
   almighty, awfully, considerably, egregiously, eminently,
   enormously, especially, exceptionally, excessively,
   extraordinarily, extremely, far and away, greatly, hugely,
   immeasurably, incomparably, inimitably, just, mightily, mighty,
   notably, only too, par excellence, paramountly, parlous, powerful,
   powerfully, preeminently, pretty, prominently, quite, real, really,
   remarkably, right, so, strikingly, superlatively, supremely,
   surpassingly, terribly, terrifically, the most, to crown all,
   transcendently, very, vitally