You may have noticed public figures using the verb decimate to mean utterly destroy. For example, President Trump recently described U.S. action against Iran as having “completely decimated” the country’s military and economy. That usage is common today, but the word’s roots tell a narrower, older story.
Decimate comes from the Latin decimatio, built on decimus, “tenth.” In ancient Rome decimatio was a harsh form of military discipline: when a unit was judged collectively guilty of cowardice or mutiny, it could be punished by killing one of every ten soldiers. As historian Gregory Aldrete explains, the condemned unit would draw lots, and every tenth man was executed by his nine comrades. The idea was brutal and precise — inflict enough loss to terrify and restore order while keeping most of the unit intact.
A famous episode recorded by Plutarch and Appian occurred in 72 B.C. during the Third Servile War. Marcus Licinius Crassus, confronting Spartacus’s rebellion, is said to have ordered a decimation after a unit fled the field. Scholars debate his motives; some, like Barry Strauss, argue the extreme sanction was meant to shock the army into discipline and that Crassus judged the political cost acceptable.
Over centuries the meaning broadened. Related Latin usage and biblical translations tied the root to tithing — giving a tenth — and the term faded after the Roman era. Renaissance scholars revived many classical terms, and decimate began to shift: first to senses like “leave only a tenth,” then more generally to “devastate.” By the mid-1600s it was already used to mean severe destruction.
That expansion annoys language purists. In 1870 Richard Grant White derided wide uses equating decimate with wholesale slaughter. Modern lists of “banished” words have flagged it, too. But editors and linguists note that meanings change over time; usage by new generations often becomes standard as older prescriptions fade, a point defended by copy editors like Preeti Aroon.
In short, decimate started as a specific Roman punishment of killing one-tenth, then traveled through religious and scholarly contexts and eventually broadened into a common synonym for devastating. That history explains both the objections from some speakers and why most listeners accept its current meaning.