I am generally not a prescriptivist and I am aware of how language evolves. But that doesn’t mean that certain usages don’t bug me, and I will defend prescriptivism in the one area where I think it matter most–allusions to literature, myth, fable, and so on.
The Misused Terms That Bug Me the Most:
A button down shirt is a shirt with a collar that buttons down. The term is not a generic term for “shirt with buttons.” A button-down shirt is less formal than a dress shirt (and, in fact, the “Oxford Cloth Button-Down,” or OCBD, a button-down shirt made of somewhat rougher fabric than a dress shirt, is probably my favorite kind of shirt).
The term “shirt” traditionally referred to “shirt with long sleeves and a collar that buttons down the front,” since it was the primary kind of shirt that men wore, and you needed to add a modifier to clarify that you were talking about a different kind of garment (e.g., t-shirt, Hawaiian shirt, polo shirt) or to clarify what specific type of shirt you were referring to (dress shirt, flannel shirt).
But this kind of shirt is not longer the main shirt many people wear: t-shirts, polo shirts and so forth are many adults’ daily attire. So the word “shirt” by itself has come to mean any sort of torso covering that is not a jacket. (Even some things which arguably are jackets, e.g. hooded sweatshirts, are called “shirts” now.)
As a result of all this there is a gap, at least in American English, for a word that means what “shirt” used to mean. So people have taken it upon themselves to refer to long-sleeved collar shirts that button in the front as button-down shirts, no doubt reasoning that these shirts, after all, “button down” the front. But the word seems only to refer to shirts that are slightly fancy–people do not refer to plaid flannel shirts as button-down shirts, for instance.
The primary difficulty with this new usage is that it is now difficult to refer to a “button-down shirt” in the old style and have people understand what you mean.
I would suggest that all people henceforth cease misusing the term button-down shirt and begin calling such shirts “dress shirts.” Now, this term would include some shirts that are not very fancy–you wouldn’t wear them with a suit to a job interview. I am aware of this shortcoming. Perhaps those shirts could be referred to as “fancy lad shirts.”
In all honesty, this battle may well be lost, since we do need a word to refer to “shirt with buttons and a collar” other than “shirt.” However, it is annoying to lose a word by which to unambiguously refer to the kind of shirt that has a collar that buttons down.
“Enormity” doesn’t mean “bigness,” it means “a great evil” or “the great extent of something very bad.” Yet people seem to use it to refer to “enormousness.”
This one is troubling because the word is often used to mean the opposite of its traditional meaning. For example, “The enormity of his achievement.”
While words change meaning, references to specific stories should not. These allusions should stay somewhat faithful to the source story and not turn into fossilized figures of speech.
“Splitting the baby” is an example of a bad sort of compromise that no one should want. It does not mean “simple compromise.”
The “Lion’s Share” is all–100% of something. The lesson of the tale is that you shouldn’t try to split something with a lion because he will take all of it–not just “most.” Using the phrase “lion’s share” to mean just “majority” totally misses the point of the story. If a wild donkey and a lion go hunting together and the lion only takes 60% of the prey, I’d say the donkey is pretty lucky.
“Sour grapes” means “Pretending to not want something you actually do want, because you can’t have it.” It doesn’t mean “generally peeved about something.”