The telos is the end of a goal oriented process, or the last in a series.
From the Greek word for 'end'. The Greeks used it to mean end both as in 'finish', and as in 'goal'. It has survived into English (in so far as it has) because it was the fourth and final of Aristotle's causes. It was used, by Aristotle, to refer specifically to the end goal of a process. It this sense the telos exists, as a goal, even if that goal is never actually reached. (If the goal is reached, it may be called an entelechy).
These days telos might also refer to the end step of a chain of events, even if it wasn't a specifically planed goal. Telos is declining in usage, although its offspring teleology and teleological are still going strong.