The Collaborative International Dictionary
Percussing
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.
Wiktionary
percussing
vb. (present participle of percuss English)