We casually use the word “decimate” today to mean destroy something badly. But its original meaning was disturbingly precise.
The word comes from the Latin decimare, meaning “to take a tenth.” It is related to decimus, meaning “tenth,” and decem, meaning “ten.”
Why would the Romans need a word for “taking a tenth”?
Because of a brutal military punishment called decimatio.
If a Roman military unit committed a serious offense such as mutiny or cowardice, the soldiers could be divided into groups of ten. In each group, one soldier was chosen by lot. The remaining nine were then ordered to kill him.
In other words, roughly one out of every ten soldiers was executed—hence decimation.
Over time, the English word “decimate” lost this mathematical precision. Today, saying “The army was decimated” simply means it suffered devastating losses, not necessarily exactly ten percent.
And there’s another familiar relative hiding in plain sight:
Decimal also comes from the same Latin family associated with ten.
So the next time you hear decimate or decimal, remember: both words carry a little piece of ancient Rome—and the number ten—inside them.
