每十人杀一人,大批杀害
Decimation \Dec`i*ma"tion\, n. [L. decimatio: cf. F. d['e]cimation.] 1. A tithing. [Obs.] --State Trials (1630). 2. A selection of every tenth person by lot, as for punishment. --Shak. 3. The destruction of any large proportion, as of people by pestilence or war. --Milman.
decimation n : destroying or killing a large part of the population (literally every tenth person as chosen by lot)