Something tapered gets narrower and narrower toward one end — like a carrot, a candle, a church spire, or the leg of a pair of trousers that is wide at the top and tight at the ankle. The narrowing is smooth and gradual, not a sudden step. It is mostly used before the noun: tapered trousers, tapered fingers, a tapered edge. In clothes shops it is a standard word, and 'tapered jeans' is a style you can ask for by name. Because it is the past participle of the verb 'taper', it can also just be the past tense in a sentence like 'the road tapered to a path' — same idea, different job in the sentence.