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®

heedful
     adj 1: taking heed; giving close and thoughtful attention; "heedful
            of the warnings"; "so heedful a writer"; "heedful of
            what they were doing" [syn: {attentive}, {thoughtful}]
            [ant: {heedless}]
     2: cautiously attentive; "careful of her feelings"; "heedful of
        his father's advice" [syn: {careful}]
     3: giving attention [syn: {advertent}]