Decimation was a form of Roman military discipline in which every tenth man in a group was executed by members of his cohort.

What does decimated mean?

decimate \DESS-uh-mayt\ verb. 1 : to select by lot and kill every tenth man of. 2 : to exact a tax of 10 percent from. 3 a : to reduce drastically especially in number. b : to cause great destruction or harm to.

Where does the term decimated come from?

Decimate was first used in 1600 and was derived from the Latin word decimatus, which meant the "the removal or destruction of one-tenth".