Source : Webster's Revised Unabridged Dictionary (1913)

Percuss \Per*cuss"\, v. t. [imp. & p. p. {Percussed}; p. pr. &
   vb. n. {Percussing}.] [L. percussus, p. p. of percutere; per
   + quatere to shake, strike. See {Quash}.]
   To strike smartly; to strike upon or against; as, to percuss
   the chest in medical examination.

         Flame percussed by air giveth a noise.   --Bacon.

Percuss \Per*cuss"\, v. i. (Med.)
   To strike or tap in an examination by percussion. See
   {Percussion}, 3. --Quain.

Source : WordNet®

percuss
     v : strike or tap firmly; "the doctor percussed his chest and
         back"