Source : Webster's Revised Unabridged Dictionary (1913)

Single-minded \Sin"gle-mind"ed\, a.
   Having a single purpose; hence, artless; guileless;
   single-hearted.

Source : WordNet®

single-minded
     adj : determined; "she was firmly resolved to be a doctor";
           "single-minded in his determination to stop smoking"
           [syn: {resolved}]