Source : Webster's Revised Unabridged Dictionary (1913)

Bewildering \Be*wil"der*ing\, a.
   Causing bewilderment or great perplexity; as, bewildering
   difficulties. -- {Be*wil"der*ing*ly}, adv.

Source : WordNet®

bewilderingly
     adv : in a bewildering and confusing manner; "her situation was
           bewilderingly unclear" [syn: {confusingly}]