Talk to any committed language peever,* and sooner or later you’ll hear about decimate: that it properly means ‘kill one in ten’ and should not be used to mean ‘destroy a large proportion of’ or ‘inflict great harm or damage on’. This is because decimate originally referred to a practice in the Roman army of executing one in ten men in mutinous groups.
It’s the etymological fallacy: the belief that a word’s older or original meaning is the only correct one or is automatically more correct than newer, conventionally accepted ones. Words that repeatedly elicit the fallacy include aggravate, alternative, dilemma, fulsome, refute, and transpire. It’s often a vehicle for pedantic or snobbish triumphalism: I acquired this knowledge, and you didn’t, so I must display it.
Decimate is infamous in editorial circles for this reason. My rule, featured in the A–Z of English usage myths, is that if you say decimate can only mean ‘kill one in ten’, you must also call October ‘December’. (See also: quarantine for any period other than 40 days, etc.) For authoritative discussion, browse the usage notes in a few good dictionaries, starting with AHD.