[syn: terribly, atrociously, awfully, abominably, abysmally, rottenly]
The Collaborative International Dictionary of English v.0.48:
Abominably \A*bom"i*na*bly\, adv.
   In an abominable manner; very odiously; detestably.
   [1913 Webster]
WordNet (r) 3.0 (2006):
abominably
    adv 1: in an offensive and hateful manner; "I don't know anyone
           who could have behaved so abominably" [syn: detestably,
           repulsively, abominably, odiously]
    2: in a terrible manner; "she sings terribly" [syn: terribly,
       atrociously, awfully, abominably, abysmally,
       rottenly]