Devastated by decimation

I always struggle with a bit of personal pedantry when I hear the word decimate. Its literal meaning is quite different from its modern usage. It originally meant the destruction of one in ten but now means to destroy a significant proportion.

Decimate comes from the Latin word decimare which meant the removal or destruction of one-tenth from decem for ten. It has its roots in the history of the Roman legions. After a very serious offence by an army cohort (480 men, there being ten cohorts in a legion) such as mutiny or cowardice in battle, the commander of the legion would take the decision to punish the cohort by decimation. An officer would assemble the men into groups of ten and then one man from every ten men was chosen by lot. The remaining nine men were ordered to club the man to death. The punishment was brutal and very rarely used but its existence was a strong motivator for maintaining discipline in the legions.

However, decimate, has been used since the 17th century to mean destroy a large proportion, certainly much more than ten per cent. Although it might have been incorrect then, it is now the common and accepted usage.

So knowing the history of decimate always makes me feel a bit uncomfortable with the modern usage but I guess I just have to deal with it. However, we do have to be careful when we use decimate. To take some advice from Sir Ernest Gowers’ from his book, Plain Words of 1948:

Because of the flavour of exactness that still hangs about it … we must not say “The attacking troops were badly decimated”, and still less “decimated to the extent of 50 per cent or more”.

He quotes a wonderful example of how not to use decimate:

Dick, hotly pursued by the scalp-hunter, turned in his saddle, fired and literally decimated his opponent.

I am grateful for this wise advice as it gives me some justification to still be a little bit pedantic when I hear people using decimate.