Definition of "percussion"

percussion

/pɚˈkʌʃən/

noun
countable and uncountable, plural percussions
1. (countable) The collision of two bodies in order to produce a sound.
2. (countable) The sound so produced.
3. (countable) The detonation of a percussion cap in a firearm.
4. (medicine) The tapping of the body as an aid to medical diagnosis.
5. (music) The section of an orchestra or band containing percussion instruments; such instruments considered as a group; in bands, may be separate from drum kits.
6. (engineering) The repeated striking of an object to break or shape it, as in percussion drilling.
  Quotations
  Moreover, a perfect Medal has its Profile and out-ſtroaks ſharp (Nummus aſper) and by no means rugged; the Figures clean and well poliſh'd; the Contours neatly trimm'd, and exactly round and carefully preſerv'd; that the Extancy and Relievos correſpond with the Ingraving, and have not ſuffer'd in Percuſſion; in all which, there is a certain Spirit of Antiquity and Excellency to be diſcern'd in Antient Medals almoſt inimitable.
  1697, J[ohn] Evelyn, “Instructions How to Collect, and Procure such Medals as are Antique, and Rare; and to Distinguish the True from the False, for the Prevention of Frauds and Impostures”, in Numismata. A Discourse of Medals, Antient and Modern. […], London: […] Benj[amin] Tooke […], page 201
7. (palmistry) The outer side of the hand.