“For example, ——. The Londoners do not now use, or very seldom use, this word in its original meaning; it is on their lips from morning till night, but it is a mere expletive and means nothing. Similarly with ——, which is rapidly losing its original sense. One can think of similar instances in French—for example, ——, which is now a quite meaningless expletive. The word——, also, is still used occasionally in Paris, but the people who use it, or most of them, have no idea of what it once meant.”
One is tempted to exclaim "WTF?" Or, in Harcourtspeak, "---?"