decimation
  每十人殺一人,大批殺害
  Dec·i·ma·tion n.
  1. A tithing. [Obs.]
  2. A selection of every tenth person by lot, as for punishment.
  3. The destruction of any large proportion, as of people by pestilence or war.
  ◄ ►
  decimation
       n : destroying or killing a large part of the population
           (literally every tenth person as chosen by lot)