If you read “Born With the Dead” by Robert Silverberg, you’ll run across this remarkable passage:
“They spoke in fragments and ellipses, in periphrastics and aposiopesis, in a style abundant in chiasmus, metonymy, meiosis, oxymoron, and zeugma; their dazzling rhetorical techniques left him baffled and uncomfortable, which beyond much doubt was their intention.”
Each one of those things is a rhetorical technique, and most of them were first described way back in Ancient Greece. You can tell, because many of them are based on Greek words — in fact, some of them are Greek words. Take, for example, “aposiopesis.” Its prefix, “apo-” is something you see a fair number of times in English; “apostrophe,” “apoplexy,” “apodioxis” (also a rhetorical technique, but didn’t make the cut), and so on.
“Apo-” in Greek means standing apart or being separate, although in a number of English words it seems to be used more to mean stopping or halting. “Aposiopsis” is stopping in the middle of what you’re about to say. You do this on purpose, for effect. Max Beerbohm, in Zuleika Dobson, made it quite clear: “‘If you are acquainted with Miss Dobson, a direct invitation should be sent to her,’ said the Duke. ‘If you are not …’ The aposiopesis was icy.” P.G. Wodehouse did too, in The Adventures of Sally: “‘So …’ said Mr. Carmyle, becoming articulate, and allowed an impressive aposiopesis to take the place of the rest of the speech.”
The back half of “aposiopesis” is closest to “poesis,” another Greek word that means to make something. So “aposiopesis” just means backing away from something you were about to “make.” In this case, you were about to “make” the rest of a sentence. Now, as for all those other rhetorical tricks Silverberg tossed in…