The conscious or unconcious use of meaningless sounds or words in speech such as filler words or stammerings.
From the Greek (most likely derived from Latin) embolo- or emboli-, 'that which is thrown into something else'.
I, um, may have a slight, uh, problem with embolalia, which, I'm like, trying to overcome before I, er, speak in front of a large audience, um, tonight at the awards, ah, banquet.
So this word gave me some issues. I can't find a clear etymology on the word itself, just its roots, and I can't find a history of when this word came to into use. Oxford English Dictionary doesn't acknowledge that either variation exists, so it may be a word limited to American English. The first variation seems to be the more commonly used one. And that's all I know!