decimation /dɛsɪˈmeɪʃ(ə)n/ (noun) the killing of one in every ten of a group of people as a punishment for the whole group (originally with reference to a mut

decimation /dɛsɪˈmeɪʃ(ə)n/ (noun) the killing of one in every ten of a group of people as a punishment for the whole group (originally with reference to a mutinous Roman legion).