1. 
[syn: spectacularly, stunningly]
The Collaborative International Dictionary of English v.0.48:
Stunning \Stun"ning\, a.
   1. Overpowering consciousness; overpowering the senses;
      especially, overpowering the sense of hearing; confounding
      with noise.
      [1913 Webster]
   2. Striking or overpowering with astonishment, especially on
      account of excellence; as, stunning poetry. [Slang] --C.
      Kingsley. -- Stun"ning*ly, adv. [Slang]
      [1913 Webster]
WordNet (r) 3.0 (2006):
stunningly
    adv 1: in a spectacular manner; "the area was spectacularly
           scenic" [syn: spectacularly, stunningly]