Is there an intelligence test TV writers have to fail?

[Kevin]

"Decimate" can mean "destroying a large proportion of a group" and not just "kill every tenth person in a group", which is falling out of use. (It's still utterly inaccurate to use in a situation where everyone is gone.)

On topic, anytime the myth that "people only use 10% of their brain" comes up, I have to facepalm. It just... urgh.

You know I actually had to hit a dictionary to figure out what Pete was talking about with the 90% because I didn't realize that was the original meaning of the word. I should have, but I didn't. My Webster's dictionary pretty much matched dictionary.com and the first definition makes it kinda work in his quote. http://dictionary.reference.com/browse/decimated heck they even pretty much use that as an example, minus the second sentence.

But I had never heard the word used to mean to select by lot and kill every tenth person of. which as you note in the link is the 2nd definition now and not only at dictionary.com, but in my printed dictionary too.

So even with it meaning a great number the sentence isn't completely nonsensical. A plague decimated the entire civilization, meaning that it wasn't just a few cities or just a segment, it was everyone that was subject. Assuming they are using the great number that could mean the plague killed 90% of the population not just 10%, the word is no longer specific. Now the next sentence of "There was no one left" does cause issues, because the plague didn't kill everyone, but it could have messed things up enough that other factors wiped them out.

So this brings up the whole topic of languages evolving. Words meaning change through usage. This has always been the case. Trace the history of the word fag or faggot as some obvious examples it's a cigarette, a male homosexual, a bundle of wood, a bundle of iron.

So the word decimate has changed, mostly through ignorant usage and because it has a "powerful" sound to the syllables, the hard consonants and going from a short to long vowel. Which probably lent to the meaning becoming broader.

Of course I know much less about this subject than I would like, but it's always been a bit of a passing fancy for me.

I do agree that the statement Pete posted is poorly written, but not quite for the reasons he stated.