Source : Webster's Revised Unabridged Dictionary (1913)

Heedful \Heed"ful\, a.
   Full of heed; regarding with care; cautious; circumspect;
   attentive; vigilant. --Shak. -- {Heed"ful*ly}, adv. --
   {Heed"ful*ness}, n.

Source : WordNet®

heedfully
     adv : in a careful deliberate manner [syn: {mindfully}, {advertently}]
           [ant: {unwittingly}, {unmindfully}]