Disposable cup with fold-down lid

The cup has a lid portion extending up from one side of the cup, configured to flip down into the body of the cup, along a first score line, going from convex to concave, so as to close the otherwise open top of the cup. Flaps extend preferably from the lid portion near its lateral intersections with the cup body outwardly from the cup, or alternatively from the cup body in the same area, but inwardly. In either case, the flaps overlie what might otherwise be a small gap between the lid and the cup body in that area. This reduces any possibility for liquid to escape via that small gap. In the case of the flaps extending outwardly from the lid, the flaps also tend to act as stops against excessive downward rotation of the lid, and provide an easy way to lift the lid to open the cup, if desired. The cup preferably but not necessarily has two secondary fold lines extending from the first score line to the outer edge of the lid portion, near opposite sides of the lid portion, which assists in holding the lid down once closed.