Source : Webster's Revised Unabridged Dictionary (1913)

Boastful \Boast"ful\, a.
   Given to, or full of, boasting; inclined to boast; vaunting;
   vainglorious; self-praising. -- {Boast"ful*ly}, adv. --
   {Boast"ful*ness}, n.

Source : WordNet®

boastfully
     adv : in a boastful manner; "he talked big all evening" [syn: {vauntingly},
            {big}, {large}]