I find myself increasingly annoyed by the smug idiots who say, "Decimate does not mean destroy: it means remove or kill a tenth of."
Folks, decimate may have had that latter meaning as its only meaning when the word first came into existence, but nowadays, it's perfectly fine to say The bomb decimated the city. This might not imply total destruction, but the word in modern English can mean anything up to near-total destruction. It's a perfectly fine descriptor of what a bomb can do.
People who make such foolish "corrections" are mistaking original meanings for proper meanings. Notions of proper change with the times. The next time someone tries to tell you you're misusing decimate, ask him whether he thinks his best friend is a nice person. When he says "yes," look shocked and ask him whether he really believes his friend is foolish and stupid. This is, after all, the older-- and therefore proper!-- use of the word nice.
I once heard a man of Scottish extraction claim that no self-respecting Scotsman would ever use the term "Scotch-Irish." "Scotch is a drink!" he said, to much polite laughter from a crowd that knew no better. "The proper term is "Scots-Irish." But he was wrong: "Scotch" is a perfectly serviceable term in the perfectly legitimate expression "Scotch-Irish." Wikipedia has an interesting write-up on this expression, and notes that "Scotch-Irish" is current only in North America, while "Scots-Irish" is a term of more recent invention, and is also confined to North American usage.
This makes our man wrong twice over: if "Scotch-Irish" isn't heard outside of North America (the demographic in question is apparently referred to as "Ulster Scots" in the UK), then how does calling oneself "Scots-Irish" prove that one is a self-respecting Scotsman? This terminological quibble seems to have little, if anything, to do with the monikers used in the Old Country, and that reinforces the point I'm making in this post: in trying to sound smart, don't sound stupid.
(Click this link to see the etymology of nice.)
ADDENDUM: Here's an interesting article on the "singular they."