To taper is to get gradually narrower toward one end, or to make something do that; 'tapering' is that word with -ing, so it works in several ways. As a describing word before a noun — 'tapering fingers', 'a tapering column' — it means the same as tapered. In a sentence like 'the path was tapering into the trees', it is the verb happening right now. And it can name the thing itself: 'the tapering of the blade'. There is a second, wider use worth knowing: tapering also means slowly reducing an amount until it stops. Doctors talk about tapering a medicine so a patient does not stop all at once; economists talk about a central bank tapering its buying. That sense is common in news and is really the same picture — a thing getting thinner and thinner toward its end.