Source : Webster's Revised Unabridged Dictionary (1913)

Purposeful \Pur"pose*ful\, a.
   Important; material. ``Purposeful accounts.'' --Tylor. --
   {Pur"pose*ful*ly}, adv.

Source : WordNet®

purposeful
     adj 1: serving as or indicating the existence of a purpose or goal
            [ant: {purposeless}]
     2: having meaning through having an aim; "led a happy
        purposeful life"