Abstract: A disposable lid for a cup has an annular clamp which is adapted to be seated on the rim of the cup and to grip the interior and exterior walls of the lip of the cup so as to firmly fix the lid to the cup and a frustoconical spout which extends upwardly from the rim to a liquid discharge port at the apex of the spout, the spout having a truncation in the shape of a horizontal plane tangent to the bottom wall of a horizontal cylinder and a base of inside diameter equal to the top inside diameter of the clamp so as to permit an unobstructed, non-turbulent flow of liquid from the cup to the discharge port. Preferably, the clamp has a circular rim with inner and outer edges and a bottom face adapted to be seated on a rim of the cup and an inner inverted frustoconical serrated lip extending downwardly from the inner edge and an outer frustoconical nodulous lip extending downwardly from the outer edge which cooperate to grip the lip of the cup therebetween.