Source : WordNet®

PDA
     n : a lightweight consumer electronic device that looks like a
         hand-held computer but instead performs specific tasks;
         can serve as a diary or a personal database or a
         telephone or an alarm clock etc. [syn: {personal digital
         assistant}, {personal organizer}, {personal organiser}, {organizer},
          {organiser}]

Source : Free On-Line Dictionary of Computing

PDA
     
        {Personal Digital Assistant}