The title of this post is also the title of a great (and word-wonky) article on Slate as forwarded to me by Russell Sauve. Thanks!
The first paragraph is the most important and illustrative of the ways in which language changes over time:
Suppose a friend said to you, “I know you’re disinterested, so I want to ask you a question presently.” Then he didn’t say anything. Would you be momentarily nonplussed?
The four words being questioned – disinterested, presently, momentarily & nonplussed – are all misused or, more accurately, used in their newly-evolved meaning by yours truly.
I can use momentarily in both ways, but for the other three – especially nonplussed – I’ve move on to the newer meanings.
Read the whole article. Well worth your time and much better than those “versus” and etymology posts I’m prone to doing here every so often. And while I can be a pedant about pronunciation and grammar, I’m not nearly so anal as to recognize that language is fluid because its speakers change over time.