'Fearfully' definitions:

Definition of 'fearfully'

From: WordNet
adverb
In fear, "she hurried down the stairs fearfully" [ant: dauntlessly, fearlessly, intrepidly]
adverb
In an alarming manner; "they were fearfully attacked"

Definition of 'Fearfully'

From: GCIDE
  • Fearfully \Fear"ful*ly\, adv. In a fearful manner. [1913 Webster]