The Collaborative International Dictionary of English v.0.48:

Clumsily \Clum"si*ly\, adv.
   In a clumsy manner; awkwardly; as, to walk clumsily.
   [1913 Webster]

WordNet (r) 3.0 (2006):

clumsily
    adv 1: in a clumsy manner; "he snatched the bills clumsily"

Moby Thesaurus II by Grady Ward, 1.0:

52 Moby Thesaurus words for "clumsily":
   airily, any old way, any which way, anyhow, ass-backwards,
   awkwardly, blunderingly, bunglingly, carelessly, casually,
   cumbersomely, cursorily, disregardfully, forgetfully, gracelessly,
   haphazardly, heedlessly, helter-skelter, hit and miss, hit or miss,
   hulkily, inattentively, inconsiderately, inconveniently,
   inelegantly, maladroitly, messily, offhand, offhandedly,
   once over lightly, perfunctorily, ponderously, promiscuously,
   recklessly, regardlessly, slapdash, sloppily, tactlessly,
   thoughtlessly, uncouthly, ungracefully, unguardedly, unhandily,
   unheedfully, unheedingly, unmanageably, unmindfully,
   unsolicitously, unthinkingly, unvigilantly, unwarily, unwieldily