Funky chargers...

[Roomba]

The Princeton Encyclopedia of Poetry and Poetics defines aposiopesis, which derives from siope or "silence," as: "A speaker's abrupt halt midway in a sentence, due to being too excited or distraught to give further articulation to his or her thought." It's the ultimate embracing of your high school English teacher's advice to show, not tell. Instead of saying she or he is at a loss for words, the speaker actually demonstrates it.

This rhetorical device dates back to at least the first century B.C., when Virgil used it to depict Neptune's utter exasperation with some troublemaking wind gods in the Aeneid: "How dare ye, ye winds, to mingle the heavens and the earth and raise such a tumult without my leave? You I will—but first I must quiet the waves."

Aposiopesis also crops up in King Lear, when the title character rages at his ungrateful daughters:

I will have such revenges on you both
That all the world shall—I will do such things—
What they are, yet I know not: but they shall be
The terrors of the earth.