Source : Webster's Revised Unabridged Dictionary (1913)

Regardful \Re*gard"ful\ (-f?l), a.
   Heedful; attentive; observant. -- {Re*gard"ful*ly}, adv.

         Let a man be very tender and regardful of every pious
         motion made by the Spirit of God to his heart. --South.

   Syn: Mindful; heedful; attentive; observant.

Source : WordNet®

regardful
     adj : showing deference [syn: {deferent}, {deferential}]