（沉在酒、咖啡等液体中的）残渣，渣滓the small solid pieces that sink to the bottom of some liquids, such as wine or coffee, that are not usually drunk
I wanted a last drink of coffee, but there were only dregs left. 我还想最后再喝一杯咖啡，但是只剩下残渣了。
She had drunk her coffee down to the dregs (= finished it). 她一仰头，咖啡一饮而尽。