Source : Webster's Revised Unabridged Dictionary (1913)

Painstaking \Pains"tak`ing\, a.
   Careful in doing; diligent; faithful; attentive.
   ``Painstaking men.'' --Harris.

Painstaking \Pains"tak`ing\, n.
   The act of taking pains; carefulness and fidelity in
   performance. --Beau. & Fl.

Source : WordNet®

painstaking
     adj : characterized by extreme care and great effort;
           "conscientious application to the work at hand";
           "painstaking research"; "scrupulous attention to
           details" [syn: {conscientious}, {scrupulous}]