The word, decimate, in English, means to destroy or slaughter. The word decimate comes from the Latin word decimare which means to take or destroy one-tenth. Not surprisingly, it was originally used in a military context. If a Roman legion failed its duties, this meant that one in ten legionnaires would be selected, stripped of their armour, and beaten to death; they would be decimated.
Marcus Licinius Crassus actually enforced decimation during his campaign against the renegade gladiator Spartacus. Crassus’s legate Mummius attacked the rebel gladiators earlier that Crassus demanded, and was defeated. The 500 men of the legion were deemed “cowardly” and Crassus had one tenth killed to teach them all a lesson. Decimation declined with the Roman Empire, and didn’t emerge again until WW2.
The Soviet Union’s commissars had the duty of teaching discipline and restoring morale, and often did so in the same violent manner; by injuring or killing those who showed cowardice.