Source : Webster's Revised Unabridged Dictionary (1913)

Awfully \Aw"ful*ly\, adv.
   1. In an awful manner; in a manner to fill with terror or
      awe; fearfully; reverently.

   2. Very; excessively. [Slang]

Source : WordNet®

awfully
     adv 1: used as intensifiers; "terribly interesting"; "I'm awful
            sorry" [syn: {terribly}, {awful}, {frightfully}]
     2: of a dreadful kind; "there was a dreadfully bloody accident
        on the road this morning" [syn: {dreadfully}, {horribly}]
     3: in a terrible manner; "she sings terribly" [syn: {terribly},
         {atrociously}, {abominably}, {abysmally}, {rottenly}]