In a Word: The Great ‘Decimate’ Debate

Some cling to the idea that, because of etymology, “decimate” must mean “reduce by 10 percent.” But the word’s meaning has changed.


Weekly Newsletter

The best of The Saturday Evening Post in your inbox!


Managing editor and logophile Andy Hollandbeck reveals the sometimes surprising roots of common English words and phrases. Remember: Etymology tells us where a word comes from, but not what it means today. 

Words can and do change their meanings over time. Every day, we use words in ways that would have confused or been considered errors by the native English speakers of centuries ago. It is natural for language to change over time, but it doesn’t always happen smoothly; some language mavens actively fight changes. 

And few words have created the type of vehement language arguments that decimate has.  

Decimate stems from the name of a harsh but apparently effective disciplinary action taken by the Roman army. As a punishment for and deterrent to mutiny, soldiers in an unruly squad would be forced to draw lots, and 1 in 10 of them would be executed. The word decimate stems from the Latin decem, meaning “ten,” because it involved executing 10 percent of the soldiers. 

Much later, Oliver Cromwell gave the word new life in England. In 1655, he established a decimation tax, a 10 percent tax on Royalists or suspected Royalists (who supported Charles I during the recently ended English Civil War) in order to pay for the militias Cromwell put in place to maintain order across the realm. (By way of comparison, imagine that, following the end of the U.S. Civil War, President Lincoln had tried to pay for Reconstruction by levying a 10 percent tax on anyone who had supported the Confederacy.) As you might imagine, Cromwell’s decimation tax was short-lived. 

So for much of its life, decimate and its various forms referred specifically to a 10 percent reduction — of military personnel in the former and personal wealth in the latter. But during the 19th century, English writers began more and more to use decimate in a more general sense to indicate “a great loss in number” or “a great amount of destruction.” Over time, that became the more common meaning, so that today, decimate is no longer linked specifically to a 10 percent reduction. 

Still, there are those who insist that decimate must mean “reduce by 10 percent.” Why? “Because etymology! Deci indicates 10 percent!” This sort of thinking is known as the etymological fallacy: the belief that a word’s only true meaning is its oldest or original one.  

But again, language changes, and failing to recognize that can lead to absurdity. For example, if etymology defines meaning, December must be the 10th month of the year, manure must be the act of working the land by hand, orienting yourself must mean to face east, and only stone structures can be dilapidated.

Become a Saturday Evening Post member and enjoy unlimited access. Subscribe now


  1. I’ve always thought of the word ‘decimated’ as a similar meaning/alternative word to (say) destruction or even outright annihilation. The only word starting with ‘dec’ I truly associated with the number 10 is decade.

    December is something I never think of in this sense other than knowing the ‘Decem’ has Latin and Arabic roots regarding 10 from my high school Latin class a number of years back. I have to admit I really love the look of that curlyq Arabic lettering even though I don’t understand it.


Your email address will not be published. Required fields are marked *